Yes, because air doesn't require a God to exist.
Air comes from the Elemental Plane of Air. It isn't inherently created and defined by a God. It's a basic element of reality that isn't shaped or regulated by a deity. There are deities of air that exist as personifications of air, but air doesn't inherently require those deities to exist in normal D&D settings. It exists just fine in D&D settings without gods, like Dark Sun.
If you kill the God of Death, does Death cease to exist in the world? If you kill the God of War, do all wars everywhere end? If you kill the God of Nature, does all nature die? No, because metaphysical concepts or basic physical concepts exist independent of a deity. Magic has been repeatedly shown to not work like that in D&D settings.
When all the Gods left Krynn after the Chaos War (or as it was later retconned, Takhisis hid the world away from the Gods for decades), the things that disappeared were divine magic (due to the Gods not having access to the world), and arcane magic (due to the Gods of Magic not being present to provide it). When the Gods left Krynn after the Cataclysm, Divine magic left, but Arcane magic stayed because the 3 gods of Magic were the only deities that still were present on Krynn. When a God dies on Toril, that concept doesn't disappear, fade away or go wild. . .except when it's the Goddess of Magic. When Myrkul died in the Time of Troubles, the concept of death didn't cease to exist or go wild and rampant until Kelemvor took over the portfolio. When Leira was killed, illusions didn't fade away or cease to work or become unstable.
The only place in D&D lore I'm aware of where a basic, fundamental element of the world just ceases to exist because a deity dies is when a god of magic leaves or is killed and arcane magic just vanishes, which happened in FR and DL. In both of those worlds, the "fluff" is quite clear that arcane magic is a force that is ambient in the world, originally flowing from the deities, which mortals learn to tap as the energy surrounds them, but which withers away without the deities of magic present, as if turning off a spigot of water. Divine magic lacks that intermediary, which is a direct connection from the caster to the divine. Psionics skips relations to deities entirely and comes entirely from within, making it popular with those not on good terms with deities (which was at least mentioned a few times in passing in Planescape lore, but never explored in depth)
I'm specifically presenting examples from two different major, popular D&D settings to make it clear this is not a single setting-specific expectation but a more baseline concept of D&D metaphysics.
As I understand it though, the Weave is the way for mortals to access magic. It is not the source of magic itself. Otherwise, Mystra should just turn off magic in the Nine Hells, the Abyss, ect. But she can't, because she provides the interface that allows mortals to access and effect magic, not the entirety of magic itself. Sort of how your keyboard isn't the source of the electricity and drives that makes your computer work.
And while Myrkul died, Bhaal wasn't dead at the same time. Nor was Jergal, nor was Yurtrus, or beings like Talona where their portfolios are closely related to death.
Now, I'll grant you dragonlance, but their cosmology is a bit unique. What with the three moons (which are gods) waxing and waning and magic waxing and waning with them. It makes perfect sense that with them vanishing, magic goes wonky, because they are essentially all new moons, during which time magic of that type was turned off.
And yet, did you yourself not say, that people still figured out a "new source" of magic? How could they possibly do that, if magic was gone? Unless, again, the familiar "type" of magic was gone, the easy way that was provided to them by the gods, but MAGIC writ large, still existed. Just like a wind mill lets you harness the wind, but the wind still exists and can be used, even if you don't have a wind mill.
They were put in the same Universe pretty early... Dr. Strange was looped in by June 1964 in FF 27 (so, within his first year). And that was after 1963 which was one cross-over after another at the House of Ideas to get everyone else together.
Having devices that block psionics is a regular thing in Marvel Comics. And having magic that does just about anything is a regular thing. I don't remember mutant powers or tech or psionics stopping magic in the 616 though. Do you have a favorite example?
Unfortunately I do not. A lot of my prefered "comic book" universes are not DC and Marvel, so I'm only partially familiar with them.
I do remember that Apocalypse and Galactus are kind of "undefined" though, with them doing psychic/magic/tech all at the same time.
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Honestly, with the plethora of Psionic abilities already presented as spells, and the fact that Psionic and Magic should be "transparent" or effect each other equally (Yes, you should be able to defend against psionics with magic. Mind Blank is explicitly designed for that purpose) and that fully component-less casting means you are impossible to stop (blind me, gag me, and tie me up, I can still hit you with my abilities) I just don't see the appeal of it being a separate system, except for maybe some cool things from a different style of casting.
The sheer number of issues I can see coming up, just doesn't make it worth it to me.