milton freight yard seems most likely to me.
Freight yard for who?
So, it appears as though its the Milton Line.
But the 'more trains' would, I presume, be GO trains, so odd not to have Mx present and the provincial Minister.
Maybe it'll be capital funding for a rail-under-rail grade separation somewhere near the Humber River. Get the GO trains from the south side of the existing rail line to the north side.
Previous GO documents have conceptually shown this. Not at an engineering level but conceptual. IE MS paint