Much of that twitter thread is a result of fair reasoning but he makes some of his statements too confidently and in too cavalier a manner.
And it doesn't help that there is substantial use of fan made obsolete graphics, which even if they are only for illustration, still reduces the perception of credibility.
In general, for PLA related claims, the more confident they sound, the more cautious one should be.
The more conditional and erring on the side of caution there is, the more it is worth looking into.
That particular thread doesn't tell us anything many of us couldn't already surmise, while simultaneously making various claims and dates in a more confident manner than could be reasonably defended.
