If the AHL would be too easy for him, why isn't he already in the NHL?
Let's look at some of the paths to the NHL for our defense and some comparables to Bichsel. For reference, he went 18th overall in 2022.
tl;dr : for a defensive prospect to look like an NHL regular by his D+3 year, it requires either an exceptional prospect or a miserable NHL defense ahead of them. Bichsel is not particularly exceptional IMO, and Dallas is very deep at defense. Expecting anything at the NHL level from Bichsel within the next two years is most likely going to lead to disappointment. Patience is essential.
Miro Heiskanen (2017, 3rd Overall)
Let's start on the high end. D+1 in Finland, was the best D there by a considerable margin. Next year he was in the NHL.
Esa Lindell (2012, 74th Overall)
D+1, D+2, D+3 all in Europe. He came over to the AHL at the end of his D+3 season. He spent D+4 in the AHL with a short stint in the NHL at the end of the season. Hos D+5 season was his first full NHL campaign, where he's been since.
Thomas Harley (2019, 18th Overall)
D+1 in the OHL. D+2 in the AHL. D+3 he split time between the AHL and NHL, D+4 he was back primarily in the AHL. D+5 will be his first season as an NHL regular.
Nils Lundkvist (2018, 28th Overall)
D+1, D+2, D+3 all in Europe. D+4 was split between the AHL and NHL, D+5 he was an NHL regular.
Jamie Oleksiak (2011, 14th Overall)
D+1 in the OHL. D+2 was mostly in the AHL, D+3 he split time between the AHL and NHL. It wasn't really until his D+7 (!!!) season that he finally seemed to settle into the NHL.
Patrik Nemeth (2010, 41st Overall)
D+1 and D+2 in Europe. D+3 in the AHL, D+4 also AHL with a bit of NHL time. He was back and forth between the two leagues until his D+7 year as well.
Jonas Brodin (2011, 10th Overall)
D+1 and D+2 in Europe. He then made the jump immediately to the NHL, albeit on a rather weak Minnesota defense.
Oscar Klefbom (2011, 19th Overall)
D+1 and D+2 in Europe. D+3 in the AHL, D+4 mostly NHL time.
Olli Maatta (2012, 22nd Overall)
D+1 in the OHL, D+2 he jumped to the NHL immediately and stuck. Again though, a very shallow defense on Pittsburgh.
Nikita Zadorov (2013, 16th Overall)
D+1 in the OHL, D+2 he jumped to the NHL immediately and stuck. Again though, a very shallow defense on Buffalo.
Julius Honka (2014, 14th Overall)
D+1 and D+2 in the AHL. We all know the rest from here.
Juuso Valimaki (2017, 16th Overall)
D+1 in the WHL, D+2 he split time between the NHL and AHL before temporarily returning to Finland. It wasn't until his D+6 season that he looked like an NHL regular.
Shakir Mukhamadullin (2020, 20th Overall)
D+1, D+2, D+3 all in Europe. He came over to the AHL at the end of his D+3 season. He'll start his D+4 in the AHL. He seems to be progressing well.