SRAAM was demonstrated on Hawkers own company Harrier T.52 G-VTOL (itself a two seat modification of the GR.1 with minor differences) at the request of the ministry of defence on an investigation into its viability. It was also offered to the RAF on in service Harrier models as it was a self contained system that didn't lots required complex avionics. Ultimately SRAAM was canned by a defence review and the RAF were left with the option of simply buying off the shelf Sidewinders for their then Harrier GR.3 which had already begin replacing the GR.1.
The inclusion of SRAAM was to make Harrier GR.1 more appealing as without them, it has no air to air missiles open to use as this was the only one used within its timeframe. We have no plans to remove them.
Just to clarify also "in service" has never been a requirement to be in game. If you want to switch to that standard for this case, as the previous post mentioned you then have to delete probably around 50% of the vehicles in game, 50% of shells, weaponry and ordinance and pretty much everything unique and interesting that never even gets to see the light of day anywhere else.
Historical accuracy matters, but first and foremost we are a game and the developers have their discression to make choices on things like payloads and weaponry. Same case with the Swift F.7 guns, same case with Lynx AH.1 having G-LYNXs weaponry that wasn't used in service and many other vehicles in game.