I doubt anyone in a position of power is thinking of replacing half the supposed capabilities of the never delivered MR4
Given that the Russian Navy is a shadow of its former self that is understandable - we really don't require the capacity to chase SSBN's any more
A cheapish replacement for patrolling the country's Marine Economic Zone is what is required - off the shelf (i.e keep BAe away from it at all costs), cheap to run - some refurbed P-3's would be ideal but I suspect it'll be a small buy of P-8's with the maintenance outsourced to a UK commercial operator