When exactly is patch 7.1 going to be?

I understand why you didn't release 7.1 pre-2017, but I don't exactly quite get why you haven't released it this Tuesday, since it is 2017. I know it's a big patch but I'm just curious as to why it isn't out here yet. Is it because you're still trying to find bugs or something? or is it because you need more time to lock certain things down? I'm just confused that's all. Especially since there are a ton of skins released on the PBE (7 of them) a long time ago. These are Dreadnova GP, Heartseeker Quinn and Lucian, and Warring Kingdoms Vi/Garen/Azir. Those were released around four weeks ago (and skins on the PBE are released 2 weeks prior to when they get released). It also raises a question as to why those three skin concepts were released all together on the PBE since usually there's 1-3 skins per patch and not 7.

Anyways, TL;DR: patch 7.1 isn't here yet and I'm curious as to why, since there are some things that normally point to it being here by now.

If anyone could let me know why it isn't here yet, I would be most appreciative and interested to hear! Thank you!