As far as I’m aware, the only trams to Ashton on non match days, are the Eccles- Ashton ones.
There’s always been additional ones on match days. I noticed when I used to get on at Deansgste occasionally, that they would have specials lined up on the middle platform, terminating at the ground.
Not sure if they still run, as they regularly seem to run both to Eccles and Altrincham after the game these days, so I assume they come from Alti before the game also.
Before 8pm - Eccles-Ashton every 12 mins and Media City to Etihad every 12 mins so a 6 minute service between the two
After 8pm - Eccles - Ashton every 12 mins and Altrincham to Ethad every 12 mins so a 6 minute service betwen the two...
Occasionally there are crowd-buster additional services as well...