There are currently four Iron People: the Infamous Iron Man Dr Doom after turning over "a new leaf", the Invincible Iron Man Riri Williams chosen by the AI stark to be a new Iron Man and Iron Kid/Lad Nathanial Stark(who will also was have been Kang, Immortus due to time travel) and Iron Man 2020, Arno Stark the biological son of Howard Stark who was turned into a super genius in the womb by an alien probe was in hiding till the probes death.
The Infamous Iron Man is arrested by Captain Marvel on behalf of Shield, because even if he has turned over a new leaf, he is still one of Earth's Most Wanted for, you know, everything. He initially resists, but accepts this path on the condition that he is allowed to continue his good works as part of a super-plea deal. Shield accepts, he pleads guilty to the charge of being Dr Doom and becomes leader of the Thunderbolts.
Then Shield screws him over via legal bureaucracy.
Iron Man technology becomes shield owned propriety technology, with Iron Man armour becoming standard use for shield teams and drone-armour becoming part of normal military operations first in america but soon round the world, generating massive profits for Shield.
Meanwhile AI Tony accepts this and keeps training/mentoring/helping Riri, who has more grounded adventures fighting villains and stopping disasters. Maybe do something with multiple copies of the Tony AI, maybe bring back the sentient iron man suit.