Stena have changed the sailing times twice, TfW did alter their trains to connect the first time but haven't changed them again. The overnight connection eastbound is now completely gone and westbound it has a 3 and a half hour wait.
The Rosslare - Dublin was never really a ferry connection, demand was never high for that route from Dublin. Traditionally it was the route from the south and south west via Waterford.
The usage of the line south of Wexford is very low, on merit it would have closed years ago but politically, after closing the south Wexford line it was never going to happen.
Numbers from the annual rail census are here, page 54.
Changing the time of the early train from Rosslare to give a connection to the new ferry arrival wouldn't be possible as it is a key commuter service into Dublin, arriving at 08.45.
The bus times from Rosslare to Waterford/Cork haven't changed in many years.
There is also the 370 services that were set up to substitute for the closed Waterford - Rosslare railway.
https://www.buseireann.ie/timetables/370-1691670763.pdf
What has changed is the truncation of the Dublin - Rosslare route back to Wexford, at one point it was a near 24 hour route which by default connected to all the ferries to/from Rosslare but like the rail line it carried hardly anyone south of Wexford. Bus Eireann relocated their depot from Rosslare to Wexford and saved over an hour per round trip.
Wexford - Rosslare is now primarily served by a reasonably frequent Local Link route that does have an early enough arrival for the morning Stena departure and an earlier service from Rosslare.
You won't get to the morning ferry from further away than Wexford, unless you take the latest bus from Dublin at 1am that would mean hanging around Wexford from 3.20 to 6 am.
As for waiting in the cold on arrival at Rosslare for the later train, the ferry terminal will be open and has seating.