Forgetting for a second the ridiculous notion of giving a medal, even an honorary one, to someone who was not on the team, the fact of the matter is, the USOC cannot award such a medal.
The only ones who could are the IOC. Even if they were in such a giving mood (which they would not be), I doubt feeding the ego of a selfish prick like Isaiah Thomas would even get to the idea stage, let alone merit even a cursory review.
If any US basketball players should receive a gold medal, it should be the 1972 team, who were truly robbed of their rightful glory by incompetent officials. The members of that team have felt so strongly about the decision that awarded the gold to the Soviets that they did not show up to accept their silver, and to this day not a single member has accepted their medals. Many have it written in their wills that none of their heirs should ever accept the medal. That is how strongly they feel about what occured.
And the IOC has not budged even the slightest about the 1972 teams plight, so Isaiah should not hold his breath.