It's smart.
It also was necessary from a D&D-storytelling perspective: we've had Ravnica characters show up in FR-based AL story arcs already (like in "Baldur's Gate: Descent into Avernus").
Until now, D&D could pretend that the Magic: The Gathering planes that showed up in 5e D&D were variations of the planes, rather than integrated into the ongoing M:tG story or suggestive that the ongoing M:tG story and all its planes are a part of D&D.
A Forgotten Realms set makes it very clear from both sides of the WotC coin that the Planes of Magic are part of the D&D Multiverse, and the D&D Multiverse are among the Planes of Magic. They're interconnected, and the shared universe goes both ways.
Now, this DOES open us up to some weird things like Toho Giant Monsters, Transformers, and My Little Pony: Friendship is Magic now having a canon foothold into the D&D multiverse given the stepping stone of Magic: The Gathering…