Hi Gosia,
Both the t2.medium and t3.2xlarge instances are included in the carbon estimations - they are compute usage type, and they are referenced in packages/aws/src/lib/AWSInstanceTypes.ts. Hope that answers your question :)
This raises a broader question about whether our emissions estimates API should also return the usage type(s) used in the estimation formula (compute, storage, networking or memory)... Would love to hear from the community if that would be valuable, and if so, we could maybe create an issue to discuss it on Github!