Point of clarification, that's only for upgrading the OS, not for security patches. Those go back further, with a recent example covering 10-year-old models.

Hey there, fellow 2017er! Different worlds, I know, but I'm just finding out my specific model 2017 MacBook Pro--the 13" without a "touchbar"--was the last model with a replaceable SSD, so I'm about to upgrade it to 2TB. Eventually I'll probably replace its battery, but, for now, I'm even pretty happy with the remaining battery capacity. I'm just hoping it keeps working long enough for the right-to-repair movement to force Apple back to replaceable wear-and-tear parts (particularly SSD and battery) before I have to decide whether to choose between a completely unserviceable replacement model or switching platforms again.