Ruin Explorer
Legend
If they end up stripping tieflings of their name, calling them planetouched (which as a term includes more races than just tieflings in the 2e/3e usage), and hijacking the name in favor of the 4e creatures, it would strike me as disrespectful to the original material that has a longer history within D&D.
< gets out axe, grindstone >
They already did that hijack in 3.XE, though, so it's way too late for "disrespectful". Tieflings in 2E are a kind of planetouched, with not particularly more likely to be evil than others (it's just that people thought they were), who are charismatic and intelligent (but weak and unwise). Awesome. In 3.XE, for reasons known only to designers who, imo, need a spanking, they got a charisma PENALTY (what the effin eff!?), and became a +1 LA race for no godly or ungodly reason, and they were also said to be usually evil with rare exceptions. The 3.XE version is a cruel, dim-witted mockery of the 2E version, imo.
The 4E version is totally different to either - but it has a CHA bonus at least (thank... god? someone like that

So, no, you can't really pull the "disrepectful" line out about 4E Tieflings. 3.XE already scribbled over everything cool and right about Tieflings (just go read the 2E description about how charming and self-confident Tieflings are - then compare that to 3.XE's -2 CHA and "usually evil"!), and kept only the powers (kinda) and sorta the physical appearance.
So as a Tiefling-lover (real Tieflings!), I'd be fine with 4E Tieflings walking off with the name, so long as I got to play a 2E-style Planetouched Tiefling, rather than a 3.XE-style "Charming devil? Silver-tongued devil? These phrases have no meaning to me!"-type Tiefling...
One thing that really needs to go away however is the design ethos of removing something from the game, then turning around and making a new monster and giving it the name of the one that got removed. It makes a hash of in-setting continuity, it's needlessly confusing to players, and it's lazy design.
... that already happened in 3.XE...