As part of my daily backup I usually script out all SQL jobs using PowerShell to an off-site location. As well as logins, server settings, linked servers, database and server level perms etc. And I guess it would be nice to restore msdb from a backup onto DR server but even then I would assume you would restore msdb to a test server in order to manually script out the jobs. Even if you have 50+ jobs it will be very quick to load all of them into ssms and hit execute all. Or knock up a script to cycle through a folder location and execute all scripts.

Still find it strange that your restored msdb runs jobs against the originating server