I'm not a designer of the game, I haven't even read the rules, and I'm really only on here to send to my friend who likes Hollow Knight, but I can probably answer your question; No.
One of the bigger appeals of d6 games is that almost anyone can use it. It's a lot easier to convince someone to play a TTRPG if they use a common 6 sided dice. Mainly because they aren't worried about the number of sides of a dice, and also buying a bunch of polyhedral dice can be really expensive, and people don't have the time or resources to try and get them. If you really want to play the system with the standard 7-set dice than go ahead and hack it! I'm not sure how easy it would be, but I'm sure it's at least possible.
As for the class system, I very strongly doubt they'll straight up add something like that, if they wanted it they would've included it when designing it. The D&D class system can be fun, it has it's merits and all that, but invokes a specific style of play; of less skill and strategy based, and more accumulation and growth based. Not inherently bad, just probably not what they're looking to add in a Hollow Knight RPG.
Anyways, looking from the comment, it seems like your new to the TTRPG scene. Welcome! I don't speak to many of the members, but the few I've talked to are really nice. I implore you to stay around and read some more games! TTRPGs are one of the most beautiful and interesting forms of art, and I'm glad to see someone expanding their horizons. :]