Yes the update is for 1337M
I could not find any release notes anywhere for the update.
I haven't noticed anything after the update.
Check This in mobilesyrup at bell-samsung-galaxy-s4-receiving-small-software-update
Quick update for those who have the Samsung Galaxy S4 on Bell. This one-time flagship was recently updated to OS 4.4.2 and we’ve received several tips that a small update has been pushed through. Coming in at 89.39MB, users will see I337MVLUFNE1 arrive and this brings “improved stability” and also “includes a fix for AirWatch MDM solution users who are unable to push the Microsoft Exchange profile to the device.”
Nothing groundbreaking… just good to keep up to date with the latest. Touch Applications >> Settings >> About Phone >> Software update to see if it’s arrived on your GS4.
Update: This has also arrived on Virgin, TELUS and Koodo.