The concensus seems to be the S25 line will roll out with 7.1 sometime in the January February time frame with 7.0 being rolled out around that time. The beta will probably start on selected devices in select regions before the first of the year.
According to a Samsung official post, the Beta will happen "before the end of the year" but is for developers only, and the stable version is scheduled to be released with the S25's. No further information exists from Samsung directly. You can scour fan sites, and they will give exact dates, these are all speculative, and mean nothing.
Should also point out that this information was for S24 series devices, so this may not even be the case for anything else.
