First SW received B7TL Geminis to update the fleet. Some had benefitted from mid-life refurbs in Bristol whilst others hailing from other OpCos hadn't been so treated; they have retrimmed the worst examples AFAIK. It may be that similarly, they will assess and take a view.
However, receiving some 12 year old vehicles is a world away from the past where they would receive 15 yr old Tridents to dislodge the last Olympians, and even that's better than when 18-20 year old Atlanteans (albeit in a condition that belied their years) to Devon from Aberdeen.
As it is, FSW is fast approaching a fairly balanced age profile where once the last ex London Tridents go, there will be a number of 2005 Tridents joined by 2004-2007 B7TLs and the 2009 e500s concentrated on the "tertiary" network (for want of a better phrase). There's a slew of 2016-2018 e400mmcs augmented by 2018 e200mmcs and Solos concentrated on the "primary" network. Yes, there's a gap in the 2010-2015 age bracket but there's a dearth of suitable vehicles in First Bus in that age bracket for various reasons, and arguably they don't need vehicles of that vintage at the moment in Kernow.
It'll be interesting to see what Somerset receive to oust their remaining Tridents when that cascade begins - more B7TLs?