If they were generally quiet before, they'll probably pump back up fine when you run it again. Sometimes that takes as long as 15 min of running. I guess perfect lifters should stay firm indefinitely, but sometimes they'll get the oil squished out of them holding a valve open when the motor stopped, or they're a little worn and drain down after sitting awhile, but pump up fine once the engine is started. I posted a bunch of info and a link with a bunch of info that goes into more detail. If there's alot of travel in the piston, near the full travel of 1/8", then they may be done for if they don't get hard again when the piston is pumped repeatedly, but again, see sentence #1 of this post.
More info.
Bennington Motorsports