I will never ever support the inclusion of the existing 3D Birdo design in anything ever. If they made a 3D Birdo that looked like this version (from Super Mario Advance instruction manual) than I would celebrate never having to see that hideous version again (at-least not in new games). Note...
For awhile now, it seems that every Mario game is a reboot. Even Galaxy 2 was in a separate universe from Galaxy.
Despite there being some continuity issues, they've managed to keep Zelda going without making it "dead", and Zelda has gone way further than what we're suggesting with Mario...
Remember that world-building doesn't only mean connections to other games. It's also how new elements is presented within a game. Making new locations & characters well-developed contributes to world-building. Including familiar locations & characters just adds to the development seen...
Would you like more/better world-building in (Super) Mario games?
At this point I feel like the Mario franchise is in too much of a mess regarding this. Every Mario game for awhile seems to be in its own universe, with little connection to other games. While most characters were introduced in...