My guess is that the players are laying low during the NHL/NHLPA "negotiations" or whatever you want to call them for the 2021 season. I've noticed that everyone seems to be laying low in terms of "official" interactions - no interviews with Bergy on the official Bruins site, for example.
While I'd love for them to have done something this year, I assume it takes a lot of coordination between the team and the players to make something like that happen - you need cameras, you need to find kids to receive the gifts, you need transportation.
Plus, in the COVID-era, it would certainly look like a mutated version of what they did last year - I don't want Pasta in a rent-a-Santa costume riding on a toy car in a Target like he did a few years ago.
In fact, they DO have an appropriately socially distanced initiative this year:
Boston Bruins Announce Holiday Initiatives
They're giving robots to hospitals, which are going to be able to visit the kiddos via Zoom, sing, and play a few games. Maybe they'll toss that up on the website. It's also extra awkward because Chara would definitely be helming this initiative, and he's not technicalyl a Bruin, so I understand how he can't "officially" be a part of anything.