Moving will be made to interrupt spellcasting at a point in time...

[normalforce]

Well unless it was lost in translation that's exactly how it reads. Cast is instantly halted, and the next cast is instant. What you say makes more sense, but I think it just needs some clarification.

It's ambiguous. I read "the new spell will be cast instantly", to mean a new spell can be cast as soon as the player's moment has stopped not that the next spell can be cast instantaneously, forgoing any casting time. The latter sounds like a broken game mechanic.