I can see why the ability to store a social graph and other metadata on Signal's servers would be a useful feature for users who don't want to tie their Signal data to their phone number and/or a plaintext social graph, and it would make sense to give users the opportunity to opt into that functionality. But for those of us whose social graph is our phone's contact list, having it forced upon us is a significant step backwards in terms of UX while adding essentially no value.

One of the things that made me optimistic about broad adoption for Signal prior to this change is that it was basically zero-friction for Android users to use Signal over the stock messaging app, aside from the few seconds it takes to download Signal and enter your phone number. But bugging the user for a PIN all the time is a significant reason to stick to the stock messaging app (or any other one, for that matter) and makes it a lot harder for me to recommend Signal in good faith to friends and family who don't care about privacy.