Hello. Wide AM on 2000 Proof coins is normal. The statement on the coin page is wrong. It should read:
In 1998, 1999, and 2000, there were two different intended designs: those meant for regular circulating coins and those meant for proof coins. The design of the circulating coins was meant to have a wide close "AM" of "AMERICA" whereas the design of the proof coins was meant to have a close wide "AM" of "AMERICA". Even so, some regular circulating coins were struck with the reverse proof design, and some proof coins were struck with the circulating design.
I reported it here: https://en.numista.com/forum/topic109000.html in 2021 and was closed as being done in 2022. It wasn't. I will make sure it's corrected this time.
Sorry for the misinformation.