Have you planted anything in it yet?
If not you have a couple options.
Cook it in the oven to kill everything.
Use mosquito dunks and some bug killer like SNS.
Or dump it and get something else.
It is possible but it could also be co-incidence so don't jump down that rabbit hole yet. Verify first that there are a lot of Thrips in the bag of soil. If it is just a few they might have ended up there because another source is causing the whole problem and they are now on your plant and in the bag of soil.
Lots of ways. Start off with a search here for suggestions. Do a web page search using your favorite search engine to see what other solutions are available.
To get started here is a thread from a bit over 2 years ago on Thrips.