Thinking more about this I think it could be also we're trying to get cheaper backup attacking options for the first team. Even if we won't get much for selling Deulofeu, Vidal, Denis and Paco (though I like him but would sell him for the right money and if he'll continue to play good in second half of the season there could be some good offers for him) we would save their wages. We could give that money to Griezmann who would actually be a starter and hopefully also a difference maker and then keep cheaper backups like Arnaiz and possibly Pozo with Abel Ruiz also waiting in Barça B.
Messi, Dembele, Griezmann and Suarez would be unquestionable starters (probably in 4-2-3-1) and then we'd have Arnaiz and Pozo on lower wages to play in Copa or easier games. We could also keep one of Denis or Paco to have more (proven) depth or maybe sign another versatile offensive player. Could also be a veteran in free agency (like Larsson) on a reasonable 1-2 year contract or maybe even on loan.
I know he's not on exactly low wages in Chelsea and it's unlikely to happen but if Conte leaves and whoever their next coach will be won't count on him I wouldn't mind getting Pedro back on loan.