Is your feature request related to a problem? Please describe.
I have a lot of addons that spam the chatbox upon loading.

Describe the solution you'd like
Wait until all addons are loaded, then clear the chatbox

Describe alternatives you've considered
I tried to create the addon myself (I can't, lol), I attempted to look for other addons that handle this. I did find one that is outdated that could "learn" what addon spam there is and on the next login remove it...but the addon doesn't work anymore.

Additional context
I was unsuccessful in finding an event that loaded after all addons had loaded. Then I realized that this would be more suited to be an option in Prat and probably wasn't big enough to be it's own addon.

There is StopTheSpam old addon which still works.

It's 'dangerous' to just clear the chat, as there could be other things in there - chat messages, friend/guildie came online etc. What happens if you do a reloadui mid-dungeon and people were talking in group chat?
Not sure if there's a way to just ignore addon messages for a few seconds at login. Or maybe learn the messages. Or pick which addons to block from a list to ignore at login for a few seconds.
Thing is, I also hate the addons that insist on spamming at login that they loaded, or some random message. I just tend to look for other addons to get rid of that, that annoying it is. However, there's also some informative messages that I would like to not hide (ie: TSM is rebuilding cache; Questie is reloading the database, showing a progress; friends list syncing addon showing the sync progress).