First of all note that, CN is assgined for whole AS region - start from AS00000001, and there is not necessarily 838 winners from Asia in front of AS839, typically we can assume around 400 winning cases (CNs), each winning case could have in average one derivative.
further, as per your assumption CN AS839 is very low in AS region, so it has higher chances to get an interview. also All ~400 winning cases in SL (838 selectees) spread over AS00000001 to what ever the highest CN for AS. let's say among the 400 winning cases (838 winners) in SL, 20 cases have CN above AS000025xxx, since 25k is comparatively high for AS, those winning 20 cases including their derivatives have less chance to get an interview.
In a normal year, month of interview will be determined by the Current CN range in Visa Bulletin (VB), if your CN is below the CN given in VB, you're current for that month, which implies you can expect your interview. Again please note this is applicable for a normal year. but DV22 may have some deviation due to processing delay.
finally the VISA approval/denial is Consular Officer's decision.