Typical "making nothing out of nothing" article. By the same thinking, if this Jack C fails to announce he is alive tomorrow it would be naturally assumed that he is dead. The guy is just trying to get attention by making a "news" out of a nothing.
Being serious though, every activity mentioned by CMSE in its article are NOT experiment. Did CMSE or CASC announce launch date of CZ-10A, B? Mengzhou's abort test? Or Mengzhou's high orbit reentry test years ago? I think this is just common practice in Chinese Space industry. Mengzhou's first launch is just a test.
I think Jack C (Phazee on twitter I believe) does generally good work and the ChinainSpace substack is one of the best China space progress blogs out there atm.
Ultimately trying to read tea leaves with China space is difficult, and it is not unreasonable to entertain that it may be a possibility that the first Mengzhou launch is delayed compared to what was previously expected, based on what is or isn't announced compared to past patterns/precedents.
That isn't too different to trying to predict/project new rocket launch schedules months in advance, or new rocket projects, or new payload readiness.
And Mengzhou's first launch is fairly high profile so keeping a close eye on it and trying to predict its first launch timetable is pretty reasonable.