gap after removal of laminate floor

Been laying flooring for 15 years and me personally I'd fill it eith a timber that matches skirting making sure it's solid so when carpet is tucked there is no movement or if your redecorating u could take of and have skirting lowered before fitting. If this gets left and gap stay carpet might not hold probably on to gripper rods and also don't get a nice finish when being tucked in between skirting and gripper

possible solutions. Thick underlay and carpet, try 2 smple pieces see if gap is taken up. if not Build floor up with maybe 9mm ply Other cheaper materials may be available, ask at a builders merchants