Earlier today, Rare LTD Studio Head Craig Duncan took to Twitter to clarify what the studio plans to do with Sea of Thieves as it comes to Cross Play. Apparently there were some rumors floating around that they were eliminating it from the game. However, as Craig points out in the twitter thread below, Rare will be allowing for Console players (with controllers) to Opt OUT of cross play with the future release of The Arena, the new PvP element in Sea of Thieves.
Me personally, as a player that is engaged both in PC and Console play, I think this is a smart addition and put the choice in the hands of the player as to whether to play against those that may have an advantage with superior hardware and controls (mouse, keyboard) while playing PvP. PC players could literally slaughter console players depending on their connection, hardware and peripherals (not to mention skill). So at a minimum, Rare is just making sure that the game stays fun to play and players don't have to worry about disadvantages from those with PCs that could also have potentially nefarious motives.