Second benefit for...:

2.2.5 Re-authenticating (Level AAA): When an authenticated session expires, the user can continue the activity without loss of data after re-authenticating.

... is...

In circumstances where a sign-language interpreter may be relating audio content to a user who is deaf, control over time limits is also important.

That is a fine benefit for 2.2.1 but not applicable for 2.2.5 as this is not a SC for controlling time limits