All about the match-ups. Best case scenario for me is he outranks other rushdown-y characters like the space animals or Meta Knight with his super armour and speed, but loses out to those with a good grab like Dedede. It could actually bring some nice balance to the roster to give an advantage to grab users like that. However, as far as his OHKO goes, it may just be a term and he has a bad recovery, so I really doubt he's broken.
Where I think he may be a top tier is in his fast-paced gameplay and natural ability for combos/mix-ups, giving him a high skill ceiling. If he does end up mediocre in strength, that alone will give him a niche on the competitive scene.