The medical community uses the calculus found in the CHA2DS2-VASc score. You can google an on-line calculator and derive your own score if you wish. Just be sure to put valid and current information in the fields or you'll get garbage for a score. If your score is above 1.5, you would be wise to take it (assuming cost and your body's reaction to it aren't problems). A score of 2.0 and above means a mandatory prescription for a direct-acting oral anti-coagulant (DOAC) like apixaban. Mandatory for the physician/cardiologist, not mandatory that you should take it...just a really good idea.
Your cardiologist wants you on apixaban perhaps due to one or more other risks than the now-corrected AF. But there's more; for up to six months after being rid of AF via ablation, you can still suffer a stroke from a clot dislodged from the left atrial appendage (LAA). The medical community has reckoned that quite a few strokes can be attributed to clots in the LAA long after the last episode of AF. !!!
Bottom line: while an ablation might rid you of the AF, there may be other comorbidities or risks that make staying on a DOAC for several months later wise, or even remaining on one for life. If it is well-tolerated.