No party would get in to power, which says there will be another referendum on rejoining the EU in it's manifesto. . Labour would lose many more seats than they gain and are only in power because they convinced the electorate that Labour would not have another referendum.
It is a different world now, than 2016. The UK has moved on and the EU are coming to terms, that they don't count at the negotiating table, for important world events. It is no good telling people what to do if you can't back it up and unfortunately for the EU, without the US protecting it, EU expansionism in the East of Europe is finished and indeed, you are more likely in the future to see Eastern European countries go back towards Russia, than more Eastern European countries join the EU.
Trump, as vile as he certainly is, made the EU face the truth, to be important, you have to be a military superpower and the EU is seen as weak by the other superpowers.
I hope the EU continues, but by continuously interfering in national elections, it is making more enemies than friends. Trying to suppress parties that are opposed to EU idealism, instead of listening to the concern of it's citizens, opposed to EU idealism is only going to end up one way.