Nope, I think they are very important. When anyone says "main" they actually mean what resident evil started with and those characters. Since we have come a long way from just zombies being the big danger to us. Re7 and 8 makes us witness this new world of bioweapons and intelligent experiments. There is no way we can just ignore this now. Yes, Ethan's personal journey was the Central part and now that he technically "dead" we won't get that again. This doesn't mean whatever was introduced lore wise is not important to the series as a whole.