Yes, to clarify the municipal albergues, the regular albergues, the pensions, and of course the hotels I stayed at all had blankets. In fact, in one of the municipal albergues I stayed at, I asked for a second blanket and was shown where the closet was and told to help myself. I ended up never using the synthetic hiking quilt I brought with me. Also, I just returned from two weeks on the VDLP and did not bring any sort of sleep system and I did fine. Again I stayed at a range of places from the municipal albergues to hotels and everything in between.
I walked the camino a couple more times and it was on the first, my walk on the french route where I used my own sleep system because all the blankets had been taken away in response to the pandemic. Now the blankets are back and those disposable bed coverings are gone.
Good luck in packing! Buen Camino! Robin