How can a risk come from "outside" LinkedIn related to my password? If I haven't leaked my own password, then there should be nothing to fear, and my account should be secure.
Unless of course LINKEDIN ITSELF is compromised, and leaked my password. In that case, the wording about "coming form outside LinkedIn" just smells like BS/spin to me.
Users that may no longer have access to the email on that account would have a very difficult time regaining access. But overall definitely a better idea than letting a massive number of users get locked out by someone with the hacked credentials
Why don't they invalidate the passwords all at once instead of letting -- someone -- use the potentially compromised passwords again...