I strongly believe people should be able to play a class they enjoy, as in the end that's what will keep them playing, not gear. The core reason for limiting main switching is to avoid people gearing up a toon, feel like they can't get much more out of it, and decide to switch in the middle of a tier. However, the beginning of a new tier is (after a new expansion) the best time to change main.
After discussing with the other officers, this is what I decided on :
Anyone who wishes to switch main for the new tier is allowed to do so, provided they do it within the next two weeks, and under the same conditions as returning players. This means there is no set minimum ilvl requirement, however :
We reserve the right to ask you to step out if your gear simply doesn't allow you to survive and it hinders progression. In the specific case of main switching, you would still be allowed to come in on your main this week, but not be eligible for loot (since you decided on switching).
If the toon you're switching to (or returning on) is behind on gear, you need to try your best to get up to par by farming gear outside of raid. Basically if you're allowed in raid this week, but put no effort in gearing up before next week's raid, you might be required to reach a certain level of gear before you're allowed to come back in on said toon. For normal we believe 910 to 915 should be an acceptable milestone (we have yet to see tuning), which is realistic with Argus and M+. If you need help running a high enough one to get upgrades, I will try to help whenever available.
As of right now you may only switch to (or come back as) DPS, as we are currently full on tanks and healers.
Get in touch with me or Mastric if you would like to main switch, so we can know what you will be playing. This is also valid for any returning player interested in raiding with us in Antorus (though I'm not sure quite how you ended up in this thread).