Razjah
Explorer
Some of my notes on random encounters: They are not always physical or combative, some times the players just see something, like a dragon flying by, a Bigfoot on a hill top, a bear in the woods doing bear stuff.
When something like seeing a dragon once a week becomes relevant (that dragon is now attacking) those don't feel like random encounters. Sure, that dragon may have been 5% chance roll, but now it is a plot point. These foreshadowing elements aren't true random encounters to me. I view random encounters as the fights that have nothing to do with the plot. When a fight with goblins later takes on significance, it is no longer a random encounter in my mind.
I do want to say, this is an awesome idea and a great way to get random encounters to later pick up relevance any appear like a GM who had it all planned from the start.