Prime Trilogy shouldn't be that close to new Prime, it's three games, you wouldn't want your players to get franchise fatigue. I think if indeed the port was ready and was delayed there may be strategic/business reasons or decided to add extra features. I expect it early 2020 but wouldn't be surprised if it hits on December.
But really when it comes to ports there are still many options, the most obvius would be SM3DW.
But really when it comes to ports there are still many options, the most obvius would be SM3DW.