Tucker worries me much more then Elon.
Agree.
In the "radically pro-free speech" world, there are two different approaches, that while looking similar are very different.
The first is that free speech is good because it leads to finding the truth, or because the alternative is worse. This seems to be the approach that Elon believes in. Under this view, interviewing Putin is justifiable. It can even be appropriate to allow this "historian" to express his views (on Twitter for example), because that allows people to see how idiotic his arguments are (as in the community note posted above).
The other approach is that free speech is inherently good, not because of a desired outcome. By this view, the more criticism or suppression someone gets, the more important it is to listen to what they say. This is the approach Tucker is taking, which leads him to believe that since this guy is saying things that are "forbidden" that inherently makes what he says good and correct.