This is basically a revival of Hide Final grade total, Show weighted assignment percentages .
As mentioned here How do I hide totals in my students' grade summaries?, the current option for hiding totals implies that "For courses using weighted assignment groups, assignment group totals are also hidden from students."
I find that showing assignment group totals (e.g., knowing that on average you scored 80% on quizzes so far) is useful for students. It saves students the effort of computing assignment group totals themselves.
However, I find the "grand" total of these assignment groups to be disruptive. Here are two reasons/cases (feel free to add others in the comments):
1) Although totals are accompanied by an exclamation point sign saying "beware, this total does not yet include assignments X and Y", my experience is students do not take that warning into account. Instead, they look at the "grand" total as an indicator of what their grade is likely to be like, which can be very misleading if a lot of assignments are yet to come.
2) The grand total does not behave well with extra credits. My understanding is there is no way to formally distinguish between "regular" and "extra" credits on Canvas. For grading schemes with a max above 100%, this means that the grand total is capped at 100% until a set of assignments worth more than 100% have been graded. So even if a student has fallen short on "regular" credit assignments thus far, but has earned sufficient extra credit to compensate for that, her total might look disappointing (whereas really, she's worked hard enough on extra credit and she is heading for a very good grade in the class). Again, in my experience, that can cause a lot of anxiety for students.