They may not be enforcing it, but it's still a federal felony, and they are free to (as well as within their legal rights to) enforce it at any time, for any arbitrary reason.
If you choose to openly commit US federal felonies, you should be aware that it is entirely legal for the US to choose to enforce those laws against you on the basis of entirely unrelated reasons: race, political alignment, sexual orientation, gender identity, hair color, words on your t-shirt, protected expression, articles published, opinions expressed at a conference, investigative journalism, et c. They would be entirely within their rights to seek and obtain a search warrant for your property: your office, your residence, including all computers and data, as a result of your open violation of federal law. (They oftentimes after a search warrant keep all hardware that contains any data whatsoever for months or years, and even getting it back at all can entail a months-long, five figure legal battle that you'll have to pay for up front.)
The reasons the AUSA chose you to prosecute will not be relevant to the trial, which will concern itself only with whether or not you possessed a schedule 1 substance, which is (again) a felony that may carry jail time.
When you choose to ignore US federal controlled substance laws due to state or regional decriminalization efforts, you effectively waive your 1A, 2A, and 4A civil rights.