My main reasons
- Giving Disruptor invulnerability after Purification Nova just to say after a few days that its a wrong idea and they would try giving it speed, explaining why their idea was bad in the first place.
This alone suggest that they didnt try this changes in the Internal testing at all and just whent with a teoritical " what if we do this " and just waited for the community to say if its okay or not.
- Liberator changes that basically broke the Meta and made some matches one sided, making it to early tech and very massable. No real weakness with the unit being to well round like Cyclone was in the start of the beta and even now in the later game Cyclone proves to be massable with no weakness.
- Turret change that was changed to barracks tech only but then reverted even tho no one had the chance to even try it out in the beta
I could find so many other examples but it looks like Internal Testing is either used badly or its non existent.