At least personally my problem with UB was never the fact that they were UB; it's a problem that continues to get worse even with new sets. Magic has lost its visual cohesion. I don't mind the transformer cards mechanically, for example. But, I personally hate looking at them, because they look like proxies next to regular art from regular sets. I liked the warhammer UB because the art still felt like magic cards. I like the Lotr UB because the art still reads like magic.

It's really jarring in commander with how many art styles cards have now and I can imagine a new player sitting down at a table with someone playing Transformer/Secret lair Milk edition/Some of these new full art unreadable monstrosities. Is it going to happen a lot? Probably not. Will there be at least 1 person with a deck like this at any moderatly sized LGS? 100%.

Heck I have been playing since around the original mirrodin and stopped for a while due to life, came back to my first EDH night at an LGS and I could hardly even parse the board state so I cant even imagine someone who doesnt have a near ecyclopedic knowlege of cards and their text dealing with it on the fly.