Yes it means that the valve springs have been overcome.
Understand though, that camshafts and lifters are designed to operate together
within a certain range of contact pressure, too. Exceed this, and you can rob the
cam/lifter contact patch of much needed lubrication, and fail cam and/or lifters.
You can also cause lubrication problems between pushrod and rocker, or rocker to valve,
causing excessive wear or failure of those parts of the valvetrain, as well.
Ask me how I know
(20+ years working on engines of all sorts... including some dragracing and dirt trackin'.
I've burned up a couple of brand new cam/lifter or cam/follower sets this way.
Of course, a couple times it was because I got sloppy and threw a set of springs in
without paying attention to installed height, coil bind at max lift, etc... to make a race in time.
Go much over "stock" with cam, lifter ratios, or spring pressures/lengths, and you'll
really need to be looking closely at all specs, and possibly be doing some machine work.)

Obviously you're in better shape with a roller setup, but there are still design limits.
Camshaft design has a lot to do with it, too... cams with very high lift and steep ramps
will float the valves at a much lower rpm than a more modest cam, given the same springs.

Also, as mentioned earlier, you have to make sure all the other engine components are
up to the task that you're asking the engine to do. Consider where the valves are
floating, and where you're wanting to be with RPM, and WHY.
Most of the time, simply eliminating valve float, or raising the RPM where it occurs,
is not going to gain you much in the first place, as you are already outside the power curve.
If that's the case, you're needing headwork, pistons, exhaust, carb, etc... before you
even need to think about anything else. Consider grabbing the next gear, or in the
case of our model airplanes, moving to a larger prop
Sometimes an extra few RPM isn't worth it, unless you build an all out "race" motor.