So, are the newer recvrs able to get the info higher than 65536 ?
Which would allow newer recvrs to get these other channels ?
New or old doesn't matter it is just a software limitation. Changing the software doesn't do any good unless they also change the data stream, so yes if they changed first the firmware and then the data stream then you could get those other channels. Unfortunately to do this will require that EVERYTHING which receives the data stream understand the new data stream format. That's not possible today because there's no way they could deliver firmware updates to all the different hardware out there now - some of which is not even Directv branded so they don't have ownership of the software.
That's why I suggested making such a change could only be possible after the MPEG2 shutdown in 2019, when all that old stuff goes away, and there is only one model of receiver that no longer gets firmware updates. Either they could release one more update for the H20, or decide to drop support for it (which I can tell you seems unlikely since I have activated H20s on my account as recently as two days ago) and of course deliver updates for all other H2x, HR2x, HRx4 and HS17 to understand the altered guide data stream.
Given how little love they've given OTA the last few years, the chance of them going to all this trouble to change the guide data format just to support the "missing" subchannels seems pretty remote. I could only see it happening if that wasn't the only thing they wanted to change.
One advantage of the H20's lack of firmware updates over the last few years is that they never completely removed its ability to scan for channels like they did with the AM21. If you do the initial OTA setup on it, it will find only the channels for which there is guide data, just like the AM21. However, if you select the "scan again" menu option it will find all those other stations. You don't get the program info for them since there's no guide data, but at least you can watch them which is all I care about - a lot of the Cubs games are broadcast locally on a subchannel with an ID > 65535...