I am not sure if this truly belongs on this site, but I cannot find the answer anywhere else.
I just recently started playing Warhammer 40,000, the table-top game. I play as the Tau/Farsight Enclave and have become really dedicated to their lore. An Imperial Guard acquaintance of mine, who is quite arrogant and has given me false information in the past regarding the Tau, told me that after the destruction of Mu'gulath Bay, the Imperium has turned its attention towards the Tau. The plot-armoured Ultramarines, White Scars, Dark Angels, and three IG regiments are headed for the Tau Sept worlds. He claims that Games Workshop are killing off the Tau because they are the least played faction and are replacing them with another Race.
Now, I cannot find anything verifying any of this, but he does read the Warhammer 40k books and does "know" more about the over-all lore. Is there any truth to these claims?