No. PLENTY of companies that have all sorts of issues to through rebranding, website overhauls, etc. Yahoo Answers is just a small part of Yahoo as a whole, and it was Yahoo that had the logo change (so all the areas of Yahoo also got logo changes to match the main one).
Yahoo is a big company (run by Verizon Media) and there are many parts to it (Email, Finance, Entertainment, News, etc) so some of the company changes will reflect across all the 'parts' even if those 'parts' have their own issues. A logo change doesn't make YA function better or worse. It's Yahoo's logo (not Yahoo ANSWERS' logo).