Judging by The Last Jedi material that’s been released so far, it doesn’t look like the Porgs will play into The Last Jedi’s main narrative, instead just hanging out in the background and possibly being used for a gag or two.
While Rey and Luke’s stories continue in The Last Jedi, the Porgs will be keeping them company, and as you can see in the image at the top, at least one of them will make it into the Millennium Falcon.
The Star Wars YouTube channel has also been having some fun with the fuzzy alien species through their Blip animated shorts.
After learning with the rest of The Resistance that Luke Skywalker was located on Ahch-To after piecing together the map fragments that BB-8 and R2-D2 were keeping safe, Rey traveled with R2-D2 and Chewbacca at the end of The Force Awakens to find the Jedi Master and deliver his old lightsaber back to him.