Sure, you can set the single wall charger for whatever size circuit you would install for a power sharing arrangement. Now a 14-50 can't be on a breaker larger than 50a. If your only consideration is future-proofing, I'd be inclined to run a maximum sized circuit to a small subpanel or load center, then run my single wall connector and/or 14-50 off of that. When you add more wall connectors later, you do it, by adding their circuit to the subpanel, and configuring them to share the circuit feed to the subpanel.
Example 1. You run a 100a circuit to the subpanel. From the subpanel, run wire for a 100a circuit to your wall connector, use a 100a breaker and set the WC for 80a charging. When you add WC#2, run another 100a circuit and breaker from the subpanel, connect the two WCs with a data wire, and configure them to load share the 100a.
Example 2. Same 100a circuit to the subpanel. Run wire for a 100a circuit to the WC, but use a 60a breaker and configure the WC for 48a charging. Run a 50a circuit with 50a breaker from the subpanel to a 14-50 to use as a second or backup charging circuit. This should be OK since the max load is 48a from the WC and 32a from the UMC, which fits in the total 80a load available in the 100a feeder circuit. If the inspector doesn't like it, you can use a 40a breaker on the 14-50 and not lose any actual charging capacity. When WC#2 comes along, remove the 14-50 circuit breaker, up the breaker for WC#1 to 100a, run another 100a circuit from the subpanel for WC#2, connect the two with a data wire, and configure them to load share the 100a.
If 100a is too much and you want to use an 80a feeder instead, Example 1 stays the same except you use 80a wire and breakers.