Yes, according to the few articles I read, the thrombocytopenia noticed after ARN vaccine and the one seen after adenovirus vaccine are different (although both are auto-immune)
ITP is a primary autoimmune attack destroying platelets (thrombocytes). No blood clot in this process.
Bleeding occurs because platelets fall under a critical level.
You don't need anticoagulant drugs to treat this disease.
DIC is primary thrombosis disorder: something triggers blood clots to happen in the vessels, that leads to platelets and clotting factors consumption.
In this case the fall of platelet is secondary to the clotting event.
Bleeding occurs when the platelets are two low.
Anticoagulant drugs (like heparin) are used to treat DIC, unless the platelets are too low.
DIC is not usually a primary autoimmune disease, and some specialists make a distinction between DIC and the DIC triggered by anti PF4 autoantibodies
This auto-immune DIC involving PF4 have a special name HIT (heparin induced thrombosis).
HIT was named this way, because these antibodies were discovered as an autoimmune complication in the DIC treatment with heparin.
This separation is important, because even though in both of them the low platelet count is secondary to the clotting events, the treatment is not the same:
heparin is used in classic DIC whereas in HIT you can't use it, so you need to fight the clotting with another drug.
Some specialist also make a distinction between HIT and Astrazeneca induced thrombosis, because heparin is not involved in the second.
In fact the auto-antibodies involved seem the same in both cases, but heparin as the power to activate them, and even to trigger them.
I'm sorry, I can't give a better and more synthetic explanation, it's a bit complicated
