On Meta there's a list of mailing lists that mentions "wikimedia-search",
but that list seems to be dead and the archive is full of spam.
Another list exists, called "discovery", but not listed on Meta.
https://lists.wikimedia.org/hyperkitty/list/discovery@lists.wikimedia.org/
Indeed the Discovery
<https://lists.wikimedia.org/hyperkitty/list/discovery@lists.wikimedia.org/thread/HTEAZLNPUT3W3HTLAMP6B4AXKLXPSDSV/>
list is the one I've seen get Search-related traffic. I wanted to update
the relevant Meta page
<https://meta.wikimedia.org/wiki/Mailing_lists/Overview> but got very lost
when I saw the translate tag inside a row table template with an identifier
(397). The list that's listed under Search and Discovery hasn't seen
actual traffic from anyone on the search team in over 7 years. The
discovery list I linked here is the appropriate substitute, if anyone knows
how to edit that scary template thing.