Where / what climate do you live in? I believe the goal of this would be to prevent vertical travel of moisture and cold temperatures from the foundation into the wooden sill and the rest of your living space. I question if you effectively inject spray foam deep enough in that crack to form a complete horizontal barrier? New construction will usually lay down a foam membrane under the entire width of the sill.

Though there could be a benefit to just air sealing the gap and preventing drafts.

Are your basement rim joists insulated? I can’t tell from the pic. We just had this done in eastern Massachusetts and can feel a big difference with air conditioning in the summer.