couple things wrong with your post
he does not have a good backdash. lot’s of characters can do a couple meaty jabs or shorts, and if deejay backdashes, the second attack will hit him. it’s seriously like ryu tier.
He doesn’t have great normals either, as you would put it. I suppose his lights and mediums are fairly decent, but all of his heavy normals have god awful frame data. basically all of them are negative on hit. st.roundhouse has 23 frames of recovery lol. you have to remember that needing charge to cancel into specials is a huge disadvantage in footsies. think of how most charge characters have godlike normals to compensate. Bison, chun, guile and balrog all have top tier normals. Deejay’s normals don’t even come close to competing with them.
upperbody invincibility on EX MGU means nothing. like… when will that ever be useful? it’s shit as a reversal, you need to get pretty lucky to beat anything with it.
light sobat being -4 is not unpunishable for most of the cast unless it’s totally max range. if it’s spaced well it’s usually safe.
in the ultra version before 1.04 he was joke tier.
ex upkicks didn’t hit crouchers. you could knock him down and do a meaty jab with an OS for backdash ALL DAY FOR FREE without fear of any reversal. light sobat didn’t go over lows, which was a huge nerf to his footsie game. they reduced damage on knee shot and his ultra, even though he was always known be a low damage character.
i find that most people that think he wasn’t trash before just didn’t understand him. his footsie potential was just bad. If you stand just outside of slide and light sobat range (which have basically the same range), you can whiff punish both of the moves with ease, as they are on the screen forever. If he throws a fireball at that range, you can jump it on reaction and he won’t have charge for upkicks, and if you did it right he has to either block or attempt a very dangerous anti air with a normal which will often get counterhit. if he walks forward from that range, his options are basically st.mk, slide or knee shot. If you can anti air knee shots, refrain from jumping at him when he has down charge, and know your ranges and whiff punishes, he struggles so much.
1.04 made him A LOT better. the upkicks buff and the return of light sobat made him a decent character. he’s definitely not bottom of the barrel anymore. Even still, I don’t think there are very many matchups that he straight up wins.