Very.
Your IP address is visible to relay operators. Using a VPN can help mitigate that. (But VPNs do not allow anonymity). If you want anonymity use Tor.
Notes are public (so avoid posting anything that might compromise your privacy)
DMs metadata are public. So everyone knows who you are talking to and when.
And also, generally, anyone with the right type of resources can track you. If you are taking the right measures you are making the exercise more expensive for them.
Making tyranny very expensive.