Would changing her name to Ditzy Doo increase her chances of having an official toy made for her? I'd go with whichever would give her official merchandise.
I agree with this statement. Both names have always seemed fine to me. On one hand, having a pony officially named after what fans decided to call her is awesome; on the other hand, of all the non-fan names background ponies have gotten, "Ditzy-Doo" is probably the least stupid, probably because it was created by a writer, not some monkey-suited toy executive. And either way, being able to one day go into a store, plunk down ten bucks, and walk out with our very own little plastic [insert name here] would probably be even better.
But most likely if Hasbro's decision can be swayed in any way, it will probably be by whoever shouts the loudest.
"Pinkie's brain is kind of like a supersonic missile without a targeting system." - Creature SH
"Pinkie Pie is not so much random as she is non-linear." - Dvandom