These heritage communication companies have worried about this for quite some time. Orders for geostationary satellites have been a bit off, the past few years, as these companies wait to see how the large constellations do and how much of the business they lose due to these constellations. This may be one of the reasons for the mergers.

“… which also suggests these companies have never competed very aggressively against each other to cut costs.”

I believe this is correct. Satellite communication companies have sometimes been monopolies in the regions that they cover. Inmarsat, for instance, has been the major provider for marine communications (mid-ocean ship to shore) for decades. Intelsat, however, had oceanic cables as its competitor. Satellite Television companies tend to compete with each other (e.g. Dish Network and Direct TV), and the ground competition is cable television companies (themselves monopolies in their own regions).

In the U.S., airline deregulation was very hard on the heritage airlines. The heritage airlines were regulated and controlled (virtually run) by the government, making competition difficult. In the two decades after deregulation, most filed for bankruptcy at one time or another (and Continental more than once), and several stalwarts are no longer in business. Could the space newcomers do the same to the heritage space companies as the airline newcomers did four decades ago?