well the person I saw posting this was critiquing the guy that wrote the above. The point here is to say that YMTC is going through some tough time right now. Sanctions are affecting not just the sale of US tools to China but also US customer base that these foundries have built up.I don't know what Weibo commenter is basing his fact upon. YMTC was under the radar of US congress after it has successfully become a supplier of Apple. Supplying Huawei was never mentioned as the reason why YMTC got a total ban. It is banned due to YMTC is too successful.
US congress basically doesn't give a fuck about YMTC supplying Huawei or not. If you read through the news article before the total ban, the US congress was asking the Biden administration to ban YMTC more than a year ago and shortly after Apple is attempting to use YMTC products. I don't think posting a random Weibo rumor is useful for the discussion.
It will likely affect SMIC also. I think SMIC shouldn't have spent time talking about trying to keep 20% of their revenue from America. That ship has sailed. They'd be better of just finding more Chinese customers and central gov't need to pressure more of these domestic chip designers to use SMIC and YMTC production rather than have them produced by Samsung and TSMC.