I have been advised by Southern Rail that they will be commencing improvements to Purley Oaks station over the next few weeks that will include new seating, permanent signage to replacement buses (let's hope they are not needed too often) and the addition of new landscaping/planters.
The improvements are part of the Passenger Benefit Fund. The fund is supporting a range of work across the network including waiting shelters, refurbished toilets, more seats, information screens, automatic doors, more cycle parking, refurbished waiting rooms, station planters and LED lighting.
A full list of improvements across the network can be seen here: https://www.southernrailway.com/improvingyourstations.