The FDA is distinguishing between the commercial drug COMIRATY and the Pfizer-Biontech drug candidate. Its the same drug, but Pfizer filed their approval for COMIRATY. What the FDA is saying is that COMIRATY receives full approval, but the existing stock of thr Pfizer vaccine continues its EUA (meaning they can still use it; they don't have to destroy it). Both drugs also get the EUA for teens.
What you should be focused is them granting this drug full approval based on studies that concluded in May and April. Phase 3 clinical trials have not completed and have not reported results. This is far and away the fastest the FDA has ever awarded approval. Anyone should be incredibly suspect when the normal procedures are deviated from so greatly. The FDA also did not consult its consumer safety advisory board before the decision, despite previously having committed to doing so.