Don't recall any discussion of this, has it been seen in the wild?

It is not released until October 22nd of this year.

I just notice another change in the kindle edition: Arveleg I 1409 > Arveleg I †1409
A reasonable change, as he died in battle. Like the change of Witch-king of Angmar invades Arnor>Arthedain, it is probably Estate asked for this change.
Could you check if the paper edition has this change? It's at the beginning of Appendix A (ii).

Hi zionius,
I can confirm that the paper edition has this change too! I looked into the first printing of the standard edition 2021.
I hope that helps!

Thank you, Tevildo!