Actually, and for your information, it is not true.
A little simple lesson in operations and planning:
Let's take LBA as a hypothetical example.
A current airframe based at LBA G-XXXA is off for some routine maintenance at LTN. In order to get it to LTN effectively today it will operate;
LBA - PMI - LTN
Airframe G-XXXB is currently based at LTN and is fresh out the hangar, will now operate;
LTN -PMI - LBA
This is known as an Aircraft Swap.
A week later an Ad-Hoc flight is added to the programme out of LGW, however all airframes at LGW are being used. G-XXXB is sitting on the ground this afternoon at LBA so they bring it down to LGW (ferry flight) to operate the Ad-Hoc flight mentioned.
G-XXXB will not be back in the UK in time for LBA next departure the following morning, so therefore as soon as G-XXXC arrives at LGW, and is no longer required, it is positioned as a ferry flight to LBA.
It's called flexibility, and with a large fleet that is how Thomson work. Simple.
Aircraft can be seen at a particular base for anything from 1 day to 6 weeks, but Thomson do not permanently base airframes at any one base.
To answer the question of "Will one of the new Sky-Interior fleet be based at LBA?" - Seeing as this is now the leading a/c for the 737 fleet there is probably a 75% chance it will be there at any given point.