In October 1993, the main evening Granada Tonight programme moved back to Manchester. Never heard an official reason for this, but it seems the move coincided with making the programme more magazine style, like Granada Tonight Weekend.
May also be that now the franchise renewal was done and Phil Redmond's company had lost, they felt safe to cut back as they didn't have to look good with Liverpool coverage to the ITC any more.
There was a clip on TV Ark many moons ago which would suggest that Granada Tonight was brought back to Manchester in autumn 1992, but the programme didn’t get the (awful) purple map titles until autumn 1993. I’m fairly certain as pointed out all of the shorter bulletins were swapped to Liverpool by this point. I believe the GMTV bulletins were also broadcast from Liverpool from day one.
It probably would have been a logistical nightmare trying to use the This Morning studio of an autumn or winter evening if that was the plan. (See Daybreak v1.0 studio)
Whilst Granada’s News coverage was always well liked in our house, the look of the service during the 1990’s always felt tacky, but North West Tonight pre-Gordon Burns felt so cold by comparison.