Right now the downside to safeguarding is that you are put in counterhit state and you cannot tech grabs. also if you want to block normally again you have to go trough 20 frames of cancelable endlag first. so grabs could get scary to play around since you have to choose a risky option to deal with them.
That being said, the mechanics are not 100% set in stone yet and could definitely use a bit of refinement. But we would want to get a good chunk of playtesting done first. so when we do make changes, we have a better understanding on what is working and what needs to be tweeked a bit.