EDIT: Apologies. Updated with a link to what gorhill REALLY said:
Manifest v2 uBO will not be automatically replaced by Manifest v3 uBOL[ight]. uBOL is too different from uBO for it to silently replace uBO – you will have to explicitly make a choice as to which extension should replace uBO according to your own prerogatives.
Ultimately whether uBOL is an acceptable alternative to uBO is up to you, it’s not a choice that will be made for you.
Will development of uBO continue? Yes, there are other browsers which are not deprecating Manifest v2, e.g. Firefox.
*Limit access to pornography in grade school libraries. Translated your groomer speak to English for you.
You think little kids need to view explicit material? I hope no one trusts you around children. Parents have a right and a responsibility to know and approve of the curriculum taught to their children by state schools financed by their taxes. If they do not approve they should have the right to send their children and their money elsewhere. This will be the law.