That's very unfortunate. When I installed Signal, I didn't mean to open another account in which taxable assets can be traded.
In the Wired article, they argue why this doesn't put a target on Signal's back as they are not becoming an exchange. Good for them, but what about Signal users' backs?
With this feature, the range of reasons why the authorities might justifiably want to have a look at the contents of my Signal app has just widened dramatically.
If you're using this feature in the UK, you are well advised to read the HMRC guidance on the taxation of cryptocurrency:
https://www.gov.uk/hmrc-internal-manuals/cryptoassets-manual...