Hi @ledjay and welcome to the Mattermost forums (and sorry for the late reply, must have overlooked your question)!
The new version is already here, there’s no separate changelog for Omnibus and unfortunately it’s lagging behind for whatever reason with the versions, the whole packaging seems to be done manually if I’d have to guess and it happened a few times already in the past that the Omnibust packages have not been updated on the official release day or shortly after.
Right now, the following versions are available via apt, so just upgrading will give you 7.10.2-0:
root@host:~# apt-cache show mattermost | grep ^Version
Version: 7.10.2-0
Version: 7.10.1-0
Version: 7.10.0-0
Version: 7.9.4-0
Version: 7.9.3-0
Version: 7.9.2-0
Version: 7.9.1-0
Version: 7.9.0-0
Version: 7.8.6-0
Version: 7.8.5-0
Version: 7.8.4-0
Version: 7.8.3-0
Version: 7.8.2-0
[...]