Requesting an accessible room should not be done unless you have a real need for it. They are few and far between. If a person needs a roll-in shower, or a large bathroom with grab bars to transfer from a wheelchair, they need it.
Generally a person who needs an
ECV can walk, but tends to have problems related to mobility and/or stamina but does not need the special accomodations in an accessible room.
I have found that even the rooms at the value resorts have space for an ECV. If neded, the resort will provide a shower chair at no charge.