It's good that you're thinking about how announcing team departures might affect morale, but I'd say it's a bit more important to get to the root of the issue - why are so many people getting fired?

Either you're hiring the wrong people and/or treating your staff so poorly that they simply don't care about getting fired (usually people will quit before they get fired so they don't have to explain it to future employers). Or perhaps this is some dodgy sales business where you hire a ton of people and then fire most of them that don't make impossible sales targets. I hope to god it's not the latter!