The sad/hopeful thing is that if this were to occur today, they'd likely have a much easier chance to publish on the Switch (or PS4/5 or Xbox). The big platforms have really loosened up access to their stores and SDKs.
If by "the big platforms" you mean Nintendo and Xbox, then yes. Sony is still as shitty about it as ever.
The only difference today is that it's certainly easier to find a publisher who has an SDK, so you don't have to apply for one yourself.
IIRC, getting approved for a Sony SDK requires a hefty down payment, proof of a physical office space, and you have to submit the resumes of your development team and hope Sony thinks they're good enough. Then you have to wait many months to hear back. I think you even need to have a project under development, or at least a complete design document.
Although, not sure what would get published, there's not much of a game that anyone has ever seen according to the posts on HN.
Not sure access to an SDK was really the biggest challenge.