Adding plugins almost always creates as many issues at it solves (assuming those things needed solving in the first place).

While I wasn't able to locate anything on Disconnect, I remembered that Privacy Badger had a bit of push a few years ago. A bit of Googling revealed tickets that list integration of Privacy Badger as a "won't fix".

This ticket specifically lists:

• They were working on a cookie patch that made at least some of what Privacy Badger does extraneous.

• Since Privacy Badger builds a dynamic block list over time, this is potentially unique enough for malicious scripts to fingerprint individual users.

A later ticket is clearer about the whole cookie thing:

It is useless in TBB due to these reasons:

 

• TBB runs in private mode, and extensions don't have access to cookies in this mode.

 
• TBB blocks 3rd-party cookies by default.

Adding plugins almost always creates as many issues at it solves (assuming those things needed solving in the first place).

While I wasn't able to locate anything on Disconnect, I remembered that Privacy Badger had a bit of push a few years ago. A bit of Googling revealed tickets that list integration of Privacy Badger as a "won't fix".

This ticket specifically lists:

• They were working on a cookie patch that made at least some of what Privacy Badger does extraneous.

• Since Privacy Badger builds a dynamic block list over time, this is potentially unique enough for malicious scripts to fingerprint individual users.

A later ticket is clearer about the whole cookie thing:

It is useless in TBB due to these reasons:

• TBB runs in private mode, and extensions don't have access to cookies in this mode.

• TBB blocks 3rd-party cookies by default.