Note that they don't appear to have an orbital engine yet—this thing's far too small, it has to be some kind of one-off for this demo flight. Most of the competition leaped directly to testing an engine they were developing for orbital launches, in their suborbital hops.
A booster / orbital vehicle, when it appears, should have very different characteristics. I can even imagine that some kind of compatibility standard may arise, allowing to stack custom orbital vehicles to reusable boosters, much like the standardized buses for smaller satellites that exist today.
SpaceX' Starhopper was an orbital Raptor engine. The *test vehicle* wasn't orbital, but, it's testing the in-development orbital engine and associated plumbing under flight conditions (which is useful, because... well you can see the various ways Starhopper failed at the start). Likewise, Grasshopper before that, in 2012-3, was a single Merlin engine (the Falcon 9 has, eponymously, 9).
SpaceX never flew a suborbital hop with anything other than an engine intended for orbital flight.
I think if Honda had an orbital-class reusable engine at the hardware stage, that'd be flying that to test it as much as possible. I'm not aware of any of the competitors doing otherwise. This is signalling they don't (yet?) have one.
edit: Or LandSpace, whose 10 km suborbital hop last year flew one of the methane engines their orbital vehicle has nine of.