Not sure about where you are, but here they have been in deeper than normal all spring mostly because of the drought and the lake was so far down for so long. We have lots of Hydrilla and of course now the Hydrilla is not in the shallow water where it usually is for them to hang around. So they had some go shallow and maybe more than I think, but don't think they spent much time there and especially not in numbers. I believe they have already started heading for brush piles with some still in 12' to 14' of water. When we have Hydrilla healthy and thick in shallow water we usually have at least some still in 6' to 10' of water all the way to the first of June. The last 3 years has been so different for several reasons. Spring before last the SRA dropped the water 2 feet in a short time just because it was full pool at that month (stupid thing in my book), anyway what that did was move them out to 9 1/2' and there they stayed all spring. This year because the lake was down so far (13') and (9' for much longer) there never was a good continues bite in what is normally a good bite at 6' of water.
So it should have a lot to do with your lake and what they relate to in that water as well as how long the water temp stays a little low, like below 80 degrees. Our water temp is still below 80 and I have been catching crappie suspended over 17' to 20' of water for weeks. SOme are still being caught in 12' to 14' though.