Vlad
Orion has EasyList enabled by default and that should contain
reddit.com,reddittorjg6rue252oqsxryoxengawnmo46qy4kyii5wtqnwfj4ooad.onion##.promotedlink:not([style^="height: 1px;"])
but for some reason Orion's content blocker is not parsing it correctly/for some other reason it is not being blocked.
While adding reddit.com##.promotedlink
into the custom filter list by default could work as a temporary solution, I've understood that implementing #8026 should also potentially solve this issue for good.