Yes. If the renovation opens the walls, discuss adding suitable reinforcement at the planned grab-bar locations before the wall finish goes on. Blocking between studs can give a future installer a secure fixing surface without relying on tile or wallboard alone. Plan the likely locations around the toilet, shower or bath, with the user’s needs and the intended grab bars in mind.
Record the reinforcement positions with measurements and photos before the walls are closed, and keep them with your renovation records. Later installation still needs to follow the grab bar manufacturer’s fixing and sealing instructions. If the walls are already finished, have the available support and any approved anchoring options assessed instead of assuming reinforcement is present. Include future accessibility needs in your design planning even if you do not want visible grab bars today.