Additional team and channel-related features and issues within Microsoft Teams for Education
This IS BAD UX by adding in the subject line without allowing users to turn it off.
Who approved this? Existing workflows are disrupted, do you even know your target users for this feature?
Even if you want to seamlessly add it in, ALLOW user to toggle off that feature. Sure, you have it on by default during the launch of the feature, but if you notice that a majority of your USERS are not using it, then the design is the issue. Its not something they asked for nor is it something they want.
If this is some designer's ego thinking its a great idea, and by not allowing people to turn it off and getting biased analytics showing "hey people are using this"... well you basically made a disruptive prompt that gets bad data.
By forcing users to see it and disrupting their productivity, its going to immediately reflect negatively.
I understand being inclusive to those who want it, but users should be allowed to opt into that feature or make it a simple checkbox/toggle that remembers the user's last setting with their post OR save that preference as a channel based item.
Do better.