Most of the removed options are many years old. In addition, they've all been removed in past iterations of Kubo. Some options were marked as removed in the config.md, but we still had a warning in the code to let users know they have been removed.
I think it's been long enough for all of this options, and enough Kubo iterations in order to alert the users. It is good to keep it in the config.md for now so that people can actually check. However, I think it's time to remove them from the code itself.
* fix: remove mdns_legacy
We've been running both implementations for a long, long time.
It is time to remove legacy version and lower the number of LAN packets
IPFS node produces.
See https://github.com/ipfs/go-ipfs/pull/9048#discussion_r906814717
for the Interval removal rational.