

This is very much not that!
A government hosted service would have to be in compliance with record keeping requirements. Conversations like this chat group are subject to the presidential records act and would need to be kept in case of future FOIA requests.
Signal does not do that. In fact, Signal can’t do that (because they can’t see the messages). So using Signal instead of proper government communications channels is a deliberate way to not leave a paper trail. Almost like they think they have something to hide.
Germany is Europes biggest country by population and GDP (not counting Russia and Turkey for population). It makes perfect sense for them to be the biggest spenders on defence as well.
Ironically the ultra right wing AfD party is actually against the rearmament, but that is mostly because they are Putin’s puppets. (They claim fiscal responsibility concerns but this is a laughably transparent excuse)