It means some countries had already advanced hardened satcom capacities (like France which had it for a long time, lookup Syracuse satellites, it exists since 1984) in geostationary orbit, mostly for military use. It organizes the sharing of these capacities between countries immediately, before the arrival of the IRIS² constellation in low earth orbit/medium earth orbit.
The goal is to level the playing field to prevent countries to look for non European alternatives for now, which often happen in Europe when nobodies coordinates the actions of different countries when something becomes suddenly urgent (I do not thinkg it's really, but government must always show they do something, and US companies operating constellations have good salesmen).
Yes, that's pretty much what the quote form the article says. And then IRIS² constellation will be fully an EU system that member states will be able to use. Sounds like a reduction of sovereignty to me at least for the countries that have their own capabilities.
I believe, as an european, that isn't much of a concern. We are very coupled to one another, plenty have family ties with other european citizens, share similar languages within immediate neighbours, and are culturally similar. Even religion is mostly shared. Of course, each has its own identity, not saying this isn't the case.
But without unity each one of us would just be yet another small country with a declining population, unity gives us strength.
The US leadership today thinks they are powerful enough by themselves. Quite a different perspective. Hence why sovereignty there seems to have a more patriotic meaning. I'm sure the states themselves still see the value of collaborating between themselves however.
France will keep having its own satellites anyway for some time and Eutelsat is french too, so for France not so much. I do not about the other countries having current sovereign solutions. But if you take France, Germany and Italy, they already share some military space stuff like observation satellite of optical and SAR kind (france provided the optical part, and italy/germany developed and operate the SAR satellites).
The goal is to level the playing field to prevent countries to look for non European alternatives for now, which often happen in Europe when nobodies coordinates the actions of different countries when something becomes suddenly urgent (I do not thinkg it's really, but government must always show they do something, and US companies operating constellations have good salesmen).