Unless, say, someone uploaded malicious code to a repo with a dependancy the password manager pulls in which changes that behaviour...
Some code somewhere needs to be able to decrypt all those stored encrypted passwords - that code is a _super_ high value target.
I like/use/recommend/have-paid-for 1Password for 5-6 years now - but I worry that the online and 1Password for Teams implementation - even though I trust the 1Password team to "get it right" - has got to be a really "fun" target for sufficiently motivated and resourced attackers. (If I were sitting round at the NSA looking for a fun project - automated MITM of 1Password traffic at p0wned or backdoored-by-agreement carrier or IX routers, using trusted root CA certs to create legitimate-seeming SSL certs, and on-the-wire JavaScript code injection... I reckon I could sell that to my super-sekrit-PHB as a worthwhile research project. )