This is normal, I do this all the time especially off seasons I usually take a long break off gambling activities. I'm not the all round gambling person, I limit my gambling activities to certain sports.
If the reasons why he left or took a break is not addiction related reasons then I don't see anything wrong with returning after sometime off. Life can be boring at times without gambling.

We can quit everyday and say that we're for good and yet, we can still come back. Just like you, I've got those moments too that I quit for sometime and then comes back at random moments.
Usually, these breaks are just temporary and not a real quitting that sets them apart from gambling forever. We can always have a way to get us back in gambling.
And by the time we quit, it's only words that separate us from it but then our actions can move us back anytime.