some possibilities:
- they have not been able to conclusively replicate anything and don't want to publish a negative result for fear of someone else publishing a conclusive positive result later.
- they are more careful to publish something that they are not (yet?) 100% sure about
- they don't care so much about the whole 'science in the spotlight' thing and prefer to go the traditional route of publishing after peer review of one or more papers rather than to make YT videos and having to fend off a barrage of interaction
- fear of getting it wrong.