Well, I'm a glass half full kind of guy unfortunately.
So, I would be wary. I have 8 different Pi's (0's 0W's P2B's and a 3) all running projects on the Stretch OS.
I am in no hurry at all to update to Buster as I see so many issues with it at the moment which will I am sure be fixed in the fullness of time.
So any tutorials for projects that you may pick up online will be for Stretch (and even Jessie!) I would imagine, so they may not be compatible with a Pi4 (which as I understand things, can only run Buster).
And with all due respect to Heater, he is a "seasoned pro"
when it comes to tinkering with Pi's. If you are a beginner, trying to work your way around Linux when tutorials are meant for a different version of Linux can be very frustrating and time consuming.