Hi, I'm not an expert but a handyman that's done a bit of dry rot removal and research. By the way there is lots of conflicting advice out there, but look for advice from academics and independent experts as the dry rot companies want you to believe that dry rot is the bogeyman and you have to demolish half the house and buy thousands of pounds worth of chemical treatments.
As far as I can establish, if you remove the obviously rotted wood, fungus, spores and fruits, spray the remaining area with a proprietary treatment and most importantly fix the cause, then your fine.
The reason is that the microscopic spores that lead to dry rot are ever present in the atmosphere. They only begin to grow on wood in the right dark and damp conditions. It's got something to do with the cellulose in wood.
One expert view that I read said that effectively treatment and the guarantees are pointless. They are only valid as long as the area is kept maintained and dry, therefore what are they actually guaranteeing?? If it's dry, you won't have dry rot anyway!!
My view is it will be fine provided you've fixed what was causing the damp.