Everybody is reserving languages in bounty threads, it's easy to see this and to do the same.
I wrote this message after having reserved.

In fact I reserved by contacting the team directly on Slack.

Check this spreadsheet : https://docs.google.com/spreadsheets/d/1gGK92Mhbz-JnRnk4-B8Rlk-htVxuak97d--0kH0ZDPU/edit#gid=154286656
You can see that my name is in it.