Justices are generally on the lookout for the "right set of facts", so to speak. An anti-Roe justice may yet decline to take a case challenging abortion if it seems to be a weak one that will create or uphold precedent that will support abortion rights. Not saying that this means Kavanaugh is pro-life, but it is also not clear from this that he is someone favorable to Roe either.
Justices themselves have said that no one should infer from a Supreme Court decision not to hear a case that the Court is endorsing the lower court decision. It is only a decision to not decide the case on its merits, that is all.
