There are actually quite a few other Canadian aviation forums out there as well that I contribute to from time to time. Generally, I don't get too involved in the more heated discussions so haven't been directly impacted when threads are locked or deleted (here or elsewhere). However, all forums have some level of moderation and even here at PPRuNe there are some sections that are moderated quite closely ... and I understand how that can be a necessity at times.
Truly, I haven't seen that happen very often here in the Canada section but I am sure that we get checked up on from time to time in order to ensure that we play nice.
For me, I will continue to make contributions to topics that are of interest to me or when I am able to share information in answer to questions that others might pose.