Yes. Although this specific topic is not taught consistently throughout courses and textbooks. I wrote about this here, https://www.masterorganicchemistry.com/2014/02/10/socl2-and-the-sni-mechanism/

No, because that would have to involve backside attack on an sp2 hybridized carbon (and in the middle of the ring, besides)

It’s right….it is SNi mechanism….but here it is written SN2

That’s an excellent question and one that isn’t immediately obvious. One thing I neglected to add in the MsCl / TsCl example is that a weak base (e.g. pyridine) is usually added to mop up any HCl formed, which could prevent the substitution for occurring.
Another is that in the case of the PCl3, once the phosphorus attacks oxygen you could have formation of a partial P-O double bond, which would put a formal charge of +1 on oxygen and make it a better leaving group, more easily displaced by a halide.
I’m sorry if this seems like an unsatisfying answer!