From someone that's played both games and mess around with P:M, it's understandable why they took out Brawl's upB method (outside of using Melee as a base). With wavebouncing and 5 hops (not including DJ Airdodge mechanics), his recovery was extremely strong in terms of mixing up an opponents attack that didn't cover a substantial amount of space. You'd be giving P:M Yoshi a very strong horizontal recovery as well as a good vertical recovery.
To be frank, he has extremely good tools as is to make sure he lands on the stage. With his ability to still wavebounce his Egg Lay, you can still use Brawl's method of coming down from the highest possible angle and changing up your momentum at the last minute to avoid getting hit. He'll obviously be weak when it comes to recovering from lower trajectories, but with DJ, Egg Roll, Wavebouncing Egg Lay, and his new fall speed, his should be just fine.
As for explaining things to Brawl players. Unless they've played Melee, it's not going to cater their feel in most ways since it's slower paced, more defensive, and more about recoveries than Melee. They just have to look at it as a new game. A lot of people aren't going to be able to give you the bigger picture if they haven't played Melee and Brawl enough to understand the changes as a whole. I've been doing that in the Brawl Yoshi boards while most of them don't like the changes.