Hello SonarQube Cloud Users,
To enhance enterprise, organization, and user security, a new policy will be implemented. Effective immediately, User API tokens that have been inactive for 60 days will be automatically removed.
SonarQube Cloud’s token capabilities will be further enhanced in the coming months. Please don’t hesitate to share any feedback on this important topic directly via our roadmap.
Can you elaborate a bit on this. Are you saying SONAR_TOKEN will expire if bitbucket pipeline isn’t run more often than 60 days? Or that users need to re-login to site for their accesses to still work… without UI informing them? Cause since this change we have users not seeing projects anymore, with no clue as to why. 
The change will affect the tokens you have under “My Account → Security”, and so likely your SONAR_TOKEN as well. In your case, if the token is not used elsewhere, it means that if the pipeline is not run for 60 days the token associated with it will be removed. Your user does not have to log into the UI.
Cause since this change we have users not seeing projects anymore, with no clue as to why.
If this is happening in the UI then it is unrelated to this change. Please open a new thread so that we can investigate the problem.