Another concern with mandating is that it could create some resentment in those who are not yet ready to accept that kind of help. This could potentially be managed - at least partially - in how the mandate is structured.
Does your campus use any kind of early alert system? Here we have grade reports that roll in for any student currently earning D+ or lower, failing exams, missing assignments, missing class and we get as many of those to come meet with us in the resource center as possible. In my conversations with students some have not been to tutoring because they didn't know about it, some don't go because they don't want to ask for help, and some don't seem to understand what tutoring is, how it works. With some conversation many of them become more willing to engage in using those supports.
As someone else said, normalization is much more complicated. It might get easier with larger tutoring programs that have more of a presence on campus. Perhaps having the tutoring spaces open for independent study helps? That way students can see tutoring in action, see how much it is used, and start to realize that it could work for them too.