I don't. I assume it is silent on the matter, since I probably would have heard otherwise if it wasn't. In that case, the team would have a hard time taking any disciplinary action against him without facing an uphill battle in an NFLPA grievance process.
You don't think the 49ers would look for any excuse to suspend a player who stands to earn $11M+ for sitting on the bench? LOL.
The NFL already barred the Dallas Cowboys from wearing a symbol of support for police on their uniforms.
That had less to do with a protest and more to do with the NFL's contractual obligations. I can guarantee you that their sponsorship/licensing deal with Nike for NFL uniforms has meticulous details about what players can and cannot wear on their uniforms. I'm sure the NFL would have done the same thing if a player or team wanted to wear a "Black Losers Matter" emblem -- or even American flag that didn't fit the NFL/Nike specifications.