I'm sure that SD can be transmitted in MP4, it just wouldn't take as much bandwidth as HD (i.e., very little). As to formatting, I would expect them to now make everything 16:9 such that 4:3 SD would have sidebars.
Always wondered how long they would persist in keeping up a dual (and duplicative) SD/HD service. So are there any other RX's than 625 now going away? Is 322 still running? I would be interested in seeing some (rough) timeline as to when given models went dark, going back to the 90s.
Dropping the SD will obviously clear a LOT of bandwidth on 119 for current (and more efficient) 129 HD to migrate. Also this transition means a RX-only swapout with the dish unchanged. I presume that Charlie will ask most to self-swap. Anyone still on a single-feed SD?
I've been putting off relocating my dad's dish as a tree has been growing and weakening 129 (which ain't great to begin with); last year it seemed to oddly not be that bad, but now maybe I won't have to at all.
When they started in with 129 that made my job significantly harder in accessing signal on installations.