Traditionally, updates can be downloaded before the actual live date on the patch.
The patch is downloaded but not "applied" until the friday.
I don't think we'll see live tomorrow.
We have had massive updates downloaded prior before going "live" on the local machine.
It's possible they would go "live" tomorrow; however, I think it would only make sense to hold off until friday, when the season ends and the era is done.
I don't recall them EVER "activating" a patch on the day a season started (I could be wrong - I simply can't remember all the seasonal patches, since I started in S1).
Doing so, would be like shooting yourself in the foot - seeing as they say, over and over again; that they don't want to do any kind of updates during seasons (unless it's VERY critical). They've got no clue if it'll go as planned, when everything "fires up". That's why patches go live on Tuesdays/Wednesdays (NA/EU) and not on "the big day" - they then have a few days to sort out the last of the kinks, if there are any that needs attention right away.
Sure.. We've seen downloads happen over time before - but that was the bigger content updates - not something like the regular patches between seasons. The last one was 2.4 and before that, it was.. ehm.. I can't even recall - it's been so long (it seems)..
Tagger, the devs had stated that they would not roll out a mechanics change when leaderboards can be affected. If the leaderboards have closed, I can see them rolling out the patch. It could even be 1 second after the era ends. I don't see them doing it before then because it could adverse affect the leaderboard. (which is something they have said they would refrain from doing).
Now some might have rolled out before the actual season started, but when it came to season specific legendaries, this was limited to seasons start of course and should not affect the leaderboards.
Shrug. Guess, we'll know in 24 hours.
Maybe we are splitting hairs over semantics?
Patch happens tommorrow, changes go live at seasons start or after era ends? Does that make sense?
2.4.1 if goes to plan should technically speaking appear within 24 hours after the ptr ending. The patch never happens as the new season starts because things could go very wrong and they need a few days just incase beforehand to iron things out if need be. And yes the changes will already be active in NS game once you have the patch and yes that is prior to the new season beginning.