Daylight savings rules change, somewhere around the world, several times a year.
For example, between 2011 and 2016 Istanbul changed their DST rules 7 times [1]. So I think you'll find a great many systems already have a way of distributing DST rule updates.
Sure, I know all about the joy of adjusting tz databases, etc.
There are a whole lot of things here in the US that have basically never required these updates.
And, well, there's all the problems where people have assumed timezones won't change, and e.g. have stored timestamps of future events in UTC in databases that really semantically are supposed to be at 9AM in a given timezone.
For example, between 2011 and 2016 Istanbul changed their DST rules 7 times [1]. So I think you'll find a great many systems already have a way of distributing DST rule updates.
[1] https://github.com/eggert/tz/blob/main/europe#L4014