That's all nice and well, but while "toot" can be both a verb and a noun describing the message that is published, similar to "tweet", "publish" is just a verb - so how do you call a Mastodon message now?
As you've already done, you can call it a "message", I call it a "post". We don't need every social media site to strictly require their own bespoke terminology merely for the sake of branding.