The filename extension has nothing to do with the executable program image file format, and didn't even do so in the days of MS-DOS.
Don't get confused about filename extensions. There's a "COM" program image file format, which is a fairly basic program image format. It was superseded by the "MZ" program image file format back in the 1980s (which in turn has been superseded by the "PE" program image file format and several others). But it has nothing to do with the filename extension.
A program image file for MS-DOS/PC-DOS/DR-DOS can have either the extension
.COM or the extension
.EXE, but the actual image file format is not dictated by this. This is as true for 64-bit Windows NT 6.1 now as it was for MS-DOS version 3.3 back in the 1980s. The filename extension does not now dictate, and (effectively, given how early in the history of MS-DOS this changed) never has dictated, the program image file format for executables.
I mention DR-DOS. In DR-DOS version 6 (if memory serves correctly) practically all of the program image files, even the ones named
.COM, were actually "MZ" format executables, and compressed ones at that. (At the time that that version of DR-DOS was released, in MS-DOS some of the program image files still used the actual "COM" format.) This is exactly the same as what you are seeing here. The names
MORE.COM, and so forth, are the names that the programs have always had, retained for compatibility. But the program image format isn't the "COM" format. It's the "PE" format.
This really shouldn't come as any surprise or shock. After all, the programs whose filenames end in ".EXE" — such as
COMP.EXE — are not "MZ" format executables as they once were on MS-DOS, but are (also) "PE" format executables; and this situation has been the case on Windows NT for what is approaching two decades. After all, only the "PE" format (of those mentioned) is natively executable on Windows NT. The "MZ" and "COM" formats are only executable by dint of a Virtual DOS Machine. All of these programs have, on Windows NT, been Win32 programs, using the "PE" format, for a long time.