So, the engines is the same as the SpaceX Shuttle (RS-25). This is a great engine but nobody would build it today. It uses a fuel-rich design and almost universally people are now building Oxidizer-rich staged cycles. BlueOrigin BE-4 being a good example.

Second these RS-25 use hydrogen but currently everybody is building methane based engines. Building a new hydrogen engine would maybe make sense for upper stages in some situation but then you would probably copy the RL-10 or the new BE-3U that BlueOrigin is working on.

So I don't think that any modern project will try the same route as the RS-25 did.

The SLS is using new solid boosters that are not worth copying unless you want to build gigantic nukes. Solid fuel just does not make sense in space flight currently (outside a few specialised applications).

On the upper stage they will use very good but old and expensive engines (both in Block 1 and Block 1b).

Structurally the SLS is also behind the times. I don't think anybody would design something like it, they were just forced to use old stuff they had from the Space Shuttle.

So I don't think anybody would still copy SLS. Yes, SpaceX uses much of the old US and Russian ideas but in there current design, Falcon 9 they have already improved on pretty much everything. Their next Rocket, BFR, will go way beyond anything done in any other rocket. From the engines, to the structure, to the control, to cold gas thruster, fuel integration and so on.