No.
I mean, no player is every truly untradeable. Only a Sith deals in absolutes and a sith I am not. So I shall amend my “no” to a “probably not”. According to Buster Olney of ESPN, however, there might be a chance:
“But it’s possible that the Cubs will trade him [Bryant], perhaps as soon as this winter. As part of their early offseason discussions, according to sources, the Cubs have indicated to other teams they are willing to discuss trade proposals for almost all of the players on their roster and those sources say that includes Bryant.