I think it is very likely that the comics will quickly be invalidated as canon (or perhaps becoming yet another 'verse) by events in a new series (without even needing any official word and I doubt Joss is going to get much chance to say anything officially now), which I expect, going by what I have heard about them, will completely ignore them. Comic books are an "and also..." when it comes to making money, and there will be little incentive to keep as canon comics that they will be making little (if any; can they still be bought new?) money from. I would expect that, if things take off, a new series of tie-in comics will be given the go ahead.