Nextcloud’s business model is service contracts. Which is going great. The origin story of Nextcloud is that ownCloud was too commercial (open core) instead of fully open source, so they forked it. I haven’t seen any moves by Nextcloud that has moved their focus from open source to hint at enshitification. Your claims are rather bold and without proof. Nextcloud doesn’t even use LibreOffice, but the online derivative Collabora. Also OpenOffice has been dead for more than a decade so I don’t know why you even reference that. Are you confusing this with the totally different OnlyOffice (‘only’ not ‘open’) which this news is actually about?
Their fork of OnlyOffice is actually because it is open core and they want it fully open source: https://github.com/Euro-Office/#euro-office-liberates-the-onlyoffice-code-base
my advise: do not update immediately to a freshly released major version of Nextcloud. Just wait several point releases.