Half-elves

In Book 7, Chapter 30, Carl's narrative has:

I pulled up my map, looking for Lonnie. The former crawler was a half-elf, meaning he'd been from a relatively early season.

Have we had any other sign that there was a time when half-elf had been removed as an option (which sure sounds like something High Elves would want).

We know it was an option this season: Both Quan Ch and some number of Langley's car salesman/archer party were half-elves.

And Mistress Tiatha is a half-elf. She's going to be a full citizen when her indenture is over (her drunken ranting asserts that it's not going to count somehow, but seems to affirm she will be one), so her season was some time after Tipid's (4th edition) and Odette's.