It's been like this for a while, and the project owner's attitude is pretty negative overall. I do use signal daily, but I believe it's likely compromised ala lavabit.
What's in the Signal server to be compromised?
List of phone numbers? Pairs of communication partners? Timing and size of messages? Metadata about transferred media? There is still a lot, sufficient for targeting a drone strike as the usual wisdom goes.
Being able to hide from a government that wants to drone you while still being in the cellphone network requires much much much more OPSEC than just using Signal. For an average user Signal is about protecting the content of your messages, not your network, and it's good at that.