Update image sequences
By default Premiere Pro doesn't update image sequences, like After Effect does. Whenever new files are added to image sequence, you will need to offline media and relink it to image sequence again.
With Watchtower image sequences will be updated, turn auto sync on and it will happen in background.
In Premiere Pro CC2017, CC2018 each time image sequence updates its frame rate will be reseted to projects default (it could be found in Preferences/Media/Indeterminate Media Timebase)