Renovation question relating to pool beam and shallow depth

Hello, I am in the process of obtaining quotes for my pool renovation. We currently have Kool Deck cantilever, that will need to be removed. We are installing travertine / marble pavers and coping. One PB states that he need to "saw cut pool deck 12" for a relief cut. Rebar, pin and epoxy the perimeter deck to the pool beam." Another PB, states that he only needs to cut it back 3" or so...and will also "drill and pin pool deck to pool shell with rebar and epoxy."

Any ideas why one...

Renovation question relating to pool beam and shallow depth