This actually appears to be the case for all the "Move Speed" modifiers.
Related confusion/bug: The vitality stat modifiers except for "Move Speed" never appear in the "Modifies" section of the abilities. Another exception is "Healing Booster" shows "Health Regen" but other upgrades like "Extra Regen" and "Reactive Barrier" which impact the same stat do not show the "Health Regen" modifier. vs