The flip side of changing eras is that the number of international weekly commuters will have reduced following a certain political event.
Yeah, Kent stops shouldn't be at the expense of the core hourly service. I could see an argument for a future service pattern along the 1tph fast Paris, 1tp2h Amsterdam, 1tp2h Frankfurt, 1tp2h Interconnexion Est and beyond (Disney/Avignon/Ski train/Italy/Switzerland etc.) and 1tp2h stopping Paris.
That's less Paris services than today. There are currently 17 / 18 Fast services over 13 hours scheduled for Wednesday / Friday.
There's space for up to 4/5 services per hour, so that enables:
2 tph Paris Fast*
1 tph Brussels (continuing to Rotterdam and Amsterdam one hour, Köln and Frankfurt the next)*
1 tp2h Paris slow (Ashford, Calais Frethun)*
1 tp2h Marne-la-Vallee (extending to Geneva 2/3 tpd, Milan 2 tpd, and possibly South of France and Ski train)
At least 1tph Lille stops, spread across the services with * , depending on capacity and LGV nord timetabling constraints.
Out of these, I think the 2 tph Paris will happen, the 1 tph Brussels likely will happen IF the Frankfurt route happens. The paris slow is unlikely, even when Ashford and Calais were served, the service was only a few trains per day. A returned Marne-la-Vallee service would likely be irregular, driven by the long distance destinations instead of 1tp2h.
so more likely would be something like:
2 tph Paris Fast
1 tph Lille, Brussels, Rotterdam (1tp2h), Amsterdam (1tp2h), Köln (1tp2h) Frankfurt (1tp2h)
Irregular Marne-la-Vallee, (Geneva, Milan, Ski Train (if it returns), South of France (if it returns))
If the Ski Train and South of France do return, you could do a MLV shuffle instead of a Lille shuffle.
From a purely timetabling point of view - the London - Brussels - Amsterdam/Frankfurt standard paths would have 20 minutes of festering time if using the standard xx04 (and theoretically 34) path - so there should be enough slack for an Ebbsfleet or an Ashford call.
The festering time is all after the channel tunnel, because the Channel tunnel paths and paths north of Brussel don't line up. You can't use that time for stops before the tunnel. And if you could move the tunnel time, then you can just depart St Pancras later and avoid the long wait.