The first few iterations of the R3 plan showed, initially, Terminal 6 just west of T5, roughly astride the A3044 Stanwell Moor Road, and three T6 satellites (with provision for a fourth) between 09L/27R and R3. The satellites were oriented N-S so that the stands pointed E-W. The main "T6A" had no provision for aircraft stands connected to it, only those on the satellites.
The "optimised" version that superseded the above (with R3 moved further south so as not to impinge on the current M4/M25 interchange) no longer had room between the runways for satellites oriented N-S, so they were rotated to be aligned E-W (stands pointing N-S) and reduced in number to two satellites.
The July announcement implied that T6A was no more and that the capacity of the existing terminals would be expanded instead. Where that leaves the previously planned satellites remains to be seen.
Clearly, increasing runway capacity (and movements) by up to 50% isn't feasible without a corresponding increase in the number of stands, so they will have to go somewhere.