Even without a publisher and distributor they can still add to Steam. My recollection (pre-360 days) is that in the event of a publisher change MS allows developers to continue to add content provided they own the IP; PSN I haven't looked at since early PS3 days, but my recollection is the same applies.
Steam will be the easiest route, but the question will be if, without a publisher and distributor, they can secure simultaneous release on all three platforms. If they can't that may be the cause of the silence. Consoles may be in for a shock due to how politics in that domain works.
However, assume they can get someone (THQNordic for example could just be a distributor), they still need time to setup transfer of distribution chains, and/or access to those chains. None of this would be instant, even if they'd gotten the route.
Something most people don't seem to get is digital distribution doesn't require IOI to have a publisher in the traditional sense, nor does it require a distributor. When they get to disk releases they will require something, but regardless they don't have the issues we had even 5-6 years ago.
The other point to be made is there are three factors here: distributor (THQNordic distributes), publishers (THQNordic publishes too), and developers. IOI is a developer studio, EIDOS was their publisher, SE was the distributor. (EIDOS is/was owned by SE, so we can treat them as an imprint.) Logic suggests that losing SE means losing EIDOS, but that isn't necessarily the case: this could just be a role redistribution where IOI is free but have to secure their own funding.
There are too many variables in the air to be sure, but why look at the darkest reason when there are plenty of good reasons for the silence? Granted, it isn't helpful for/from our end, but they may be waiting for legal teams to get back to them to let them know what they can/should say.