I think it might for a little while but not for much longer.

When the influx started, the two oldest and biggest Lemmy instances, the ones maintained by the developers, and thus presumably the flagship instances, were lemmy.ml and lemmygrad.ml. Tankies are definitely overrepresented in those two instances, and since the devs themselves are tankies, there's a lot of moderation bias in favor of red fascist authoritarian regimes even in the nominally "neutral" lemmy.ml — such as them refusing to remove genocide denial or outright genocide justification, while also removing posts critical of China and so on.

You might argue that this doesn't affect you if you just pick a different instance, because the culture of that instance will be different and so will the moderation, but the problem with that is that if the vast majority of users on a network are tankies and are moderated by tankies then that's going to influence your experience of the network as a whole pretty much unavoidably unless you defederate with the largest instances and thereby intentionally hamstring yourself.

So even if you joined another instance, your experience of the site as a whole would be dominated by a tankie leaning culture via comments and posts, and that's where the reputation (deservedly) came from. And it probably did and maybe still does hamper the growth a little bit. It definitely made me, a trans anarchist, think twice about joining.

However, with the more neutral and professionally-run lemmy.world taking over as the second largest and flagship instance, and beehaw as the third (iirc), as well as the overall influx of a variety of users from Reddit, I think over time the dominance of tankies in how the network is experienced by users, even from other instances, will drastically decrease, especially as many instances defederate from lemmmygrad, and so the reputation will also fade.