Since it would appear that that the web browser was updated to remove an exploit that was also present on firmware 4.1 which happens to be the latest firmware Deja Vu privately works up to, it would appear Nintendo may have finally patched it out. Meaning if you want to use Deja Vu, do not update to 6.1. Although even if you do, since all 6.X firmwares so far carry the same fuse count, you can just downgrade to 6.0 or 6.0.1 which hexkyz has been able to get Deja Vu to work on.I'm on 6.0.1. Since I'm not using any homebrew right now, I only care about Deja Vu. Should I worried about this update?
Mike Heskin already confirmed that most of Deja Vu is still doable on 5.0.0+ (a couple of days before this 6.1.0 update)