If you open until the 500th tab, than click on the bottom right icon with the rectangle on top of another, than click new tab, it will says:” You have 500 tabs open, and 30 (this number is just my phone) older than one month. To open more you will need to close some tabs.”
Now if you click a link, it will still open a new tab, but in place of that new tab it will delete not the oldest tab, but the oldest tab within one month from the time you last use that tab. Meaning, if you open a tab more than one month ago, and another tab in one month, it will apparently delete the latter for some reason??? I don’t get why it just decide to not delete the oldest one. And yes it took me half an hour to open 500 tabs and check this because I was really bored I guess. I don’t know if this result is just my phone or not (i’m on ios 14.6 right now), so if anyone is crazy enough to test this I would like to know the result as well.