Plaintext password emailed to me in "forgot username" email?

I just requested a "forgot username" email for my Linode account. The email I received had text body as such:

Per your request, here are the following Linode.com User accounts associated with this email address:

<my plaintext password>
<my account's username>

Thank you,
The Linode.com Team

I was really confused when I saw my password in plaintext above my username, thinking I had somehow messed up and created an account with my username.

I then validated that there was no account with my password as a username by attempting to go through password reset and providing my password as a username, but never received an email to reset my password.

I am thoroughly confused and concerned - is this expected behavior? Is anyone else seeing this?