The 'what' that pops, probably, IMHO, is the investment and resources ecosystem dumped, poured, thrown, redirected, etc. to AI.
Just like the .com boom, the costs and money thrown at AI are outsized and will 'pop" as it matures. A 'pop" and leveling down to something perhaps not so outrageous is coming.
As the author states, .com popped but left the Internet still around and expanding. AI is exactly that kind of bubble.