They are not being fired they are being offered packages to pay off their contracts early.
...which is pretty much the definition of being fired as a professional footballer. If the club unilaterally terminates a contract of a player or coach, it pays a compensation fee. Unless the contract was terminated by mutual consent (aka the Mourinho exit)
Biggest mistake was probably not doing some of this in summer as going by results that squad is not good enough.
With the transfer ban in place and no incoming players available, it was impossible to rescind many contracts at once in summer. Only now with the arrival of several reinforcements, the squad can be restructured.
All that beind said, Barca B is taking yet another huge risk. Replacing half of the squad in January with no time for adaptation can backfire even worse than Eusebio's gamble last season. If this restructuring goes wrong, Barca will lose at least two years worth of talented graduates.
It's not just timing, it's the manner of these decisions and, in some cases, the decisions themselves. The likes of Bagnack were dead weight and Babunski probably doesn't have a future at this club but it's just downright unprofessional and unethical to rescind a contract like that out of nowhere.
Releasing Aitor?? The top scorer? Suarez? The keeper who has bailed this team on several occasions and then counted on the club during his injury? And then there's Grimaldo who had his contract ran down despite being the best performer in the team over the past year. These aren't cases of sacrificing ethics for the best interests of the B team. One doesn't improve the squad's results by getting rid of the best players to make room for below average ones. One doesn't send out a positive message about the good will of this club by releasing the youth players that dedicated themselves to Barcelona for random no-name signings.
You made a huge case about there not being any real mismanagement of the B team or youth system in recent years and that the Segunda division was difficult to stay in as is. And now we're here about 7 months after the fact with a poor coach, uninspiring signings, and a string of disappointing results in a lower division. And now the club's response is to let go of some of our best players for unconvincing ones? And by doing so, worsening our image and probably the position of our already struggling B team?
The way Bagnack's case was handled is mind-boggling. Just read that Gerard didn't even let him take part in training anymore. It only makes sense that Macky would try to fight the contract termination (even ethough he knows himself that he probably has no future in Barcelona).
Cancelling Suarez in the middle of a month-long recorvery is outright distasteful. He is already left out of the squad registration to make space for new arrivals, surely it would not hurt Barca too much if he could stay at least until the end of the season to finish his recovery.
Don't understand releasing Aitor either. While he is certainly not the most exciting talent to emerge from Masia, he still delivered decent results for the B team. Maybe there was something else about him that Gerard did not like, but to me there are several other players torelease before Aitor.
The Grimaldo case is unfortunate but it's difficult to blame somebody here. After playing B team for about 4 years, he understandably wanted more. At the same time, he is still not at the level of being a Barca A player. If the Levante loan had worked out, it probably would've been the best for both sides beause I honestly don't see him breaking into Benfica's starting eleven yet.
The general idea of this winter mercato is not wrong, though. The B team was in dire need of more experience and stability, even if the newcomers are not as exciting or talented as some Masia pearls. Hopefully the new mixture will be enough to keep Barca B in the league and provide a basis for the inevitable next summer overhaul.
Side rant: I've always been wondering why Barcelona wouldn't strike a partnership with a midtable club in Portugal or France. The partner club could profit from Barcelona's ressources and know-how by getting a number of players and coaching/management staff for free, similar to the Granada-Udinese exchange. Barca could send players caught between B and A teams (Grimaldo, Samper, Halilovic, Adama etc.) to have a top leagure experience in an environment somewhat similar to Catalunya.
Side rant²: Also it could've been pretty helpful to implement the Midtjylland approach of using statistics for game analysis and scouting for Barca B.