This is true. It's not an oddity with air bubbles, but with the whirlwind shield. If there's a patch of multiple air bubbles close together, it's in fact possible to "climb" the bubbles using a whirlwind shield to reach greater heights. This is how Sonic (and any character except possibly Knuckles?) can get the spade emblem in Azure Temple Zone.The Whirlwind Shield is special. You can use it with Spin while jumping, but you can also use it with Jump while falling (including running off ledges or bouncing on a spring).
After grabbing an air bubble, you fall, so the Whirlwind Shield can be used in that case; I don't think that air bubbles reset other shield abilities.
I don't think it's hard to exploit, it all depends on a map you're playing.it is so novel in thinking and hard to exploit that it shouldn't be fixed