Welcome to KF!!!
Guessing the velcro matched a multi-carry rig.
I had a Gerber Guardian Backup. I bought the optional rig.
Allowed several carry styles. The sheath was backed with velcro and it mated to the various straps and such.
Could be adapted, quickly, to belt (vertical, horizontal or inverted), shoulder or ankle setups.
Come to think on it, I had an identical rig for the Mk1 Gerber.
If you want to win an argument, it is best to stick to the truth.....or,at least, provable untruths.