"Do you need ... "? That depends on the way you would use a CMS. Using a CMS (and in previous versions) I could define a "message" content for the users, and used at any time the same content object with different values changing from time to time. Example: from now to 2020-12-14 we would say "starting 15. of Dec there will be a new version ... blabla", on 2020-12-16 we would show "From today on there is a new version, look into these features" and from 2020-12-16 on we would show another message.
If there was a CMS available there would be no need for programming. We even could leave the message there, and just define another value and/or other period. Would be quite easy, no programming, just administration of the CMS.
But there is no CMS available to us, so we have to re-invent the wheel.