Some retcons are easier to swallow than others. Goku being an alien. Gero working for the Red Ribbon Army... behind the scenes apparently, since he never actually appeared in the Red Ribbon Army Saga. It's fine. Probably helps the things that resulted from these retcons were good.
But Tights existing? Come the fuck on. Not only is it unbelievable, given she hasn't appeared or been referenced at all until now, but she's totally pointless, and to top it off, has a crappy, boring character design.