The first thing to say here is that some of the newer members of NATO clearly deserved to become members of NATO. Think of Estonia, Latvia, and Lithuania—independent countries that were invaded and annexed by the Soviet Union, and that became free and independent again only after the Cold War. It was a great thing that we admitted them to NATO. Right now they need our help, and Canada is providing some with our troops in Latvia.
I think your question goes more to those countries who are moving away from what we would call a free and democratic system. Here I'd be thinking of Turkey, Hungary, and increasingly Poland. But I would suggest that talking publicly about removing their NATO membership is waving a very, very big stick, and perhaps missing out on a lot of soft power and diplomacy and even economic pressure that could be applied before we get to that ultimate decision.
There's nothing that Russia would like more than for us to eject a country like Hungary or Turkey from NATO. This is not the time to be raising that ultimate punishment. But yes, I am concerned about what's happening in these countries, and all other forms of diplomatic and economic pressure should be considered to bring them back in line.