It doesn't say that either.

Read #6 there if you missed it. It's not very detailed, but it references the topic. If you want detailed examples of national languages suppression, search for articles about Yevsektsiya.

I've read it. What you said is this "During Stalin, it was the general policy to suppress national languages.". This just isn't the case, especially given the duration and the complexity (and contradictions) of policies in use during his tenure. There was certainly Russification. It's hard to point at any period where there was a straightforward "general policy to suppress national languages".

Even that reference does not say anything close to "During Stalin, it was the general policy to suppress national languages." There was no such general policy, the thing you link talks about the tension between the desire for centralized (typically Russian) control and the Marxist ideological demands of 'internationalism'.

There was no "tension". Formal internationalism was quite effectively replaced with persecution of ethnic and religious minorities, including suppression of languages and education. Internationalists were some groups like Makhno's anarchists. Stalin was the complete opposite.

But I think I'm wasting my time here. If you want to deny historic facts, do it elsewhere.

We're looking at the sources you came up with.