The issue of NATO membership is determined by all the members. I think it's fair to say that there may not have been complete unanimity before about which countries should join or whether indeed there was a formal application to join. In order for things to happen, you need a formal application and process of discussion. Whether that happens now, I don't know.
I'm sure there will be discussions, not only about NATO membership but also about EU membership. I think President Zelensky made it very clear, in his public announcements the last few days, that he's looking to that, and many European countries have said they're eager to have Ukraine join the EU, which in many respects has historically been just as important to Ukraine as membership in NATO.