According to ICM 7.10 documentation (Guide - 7.9-7.10. API Changes), pipelets are no longer dynamically reloaded, it is stated that reloading of changes has to be triggered.
The developer must know that there is no dynamic loading of pipelets any more. Pipelets behave like normal classes and the reloading of changes has to be trigered the same way than it has to be for other classes.
How to reload changes either on pipelets or other java classes while the server is running?
I know that pipelets use to reload if you had HotCodeReloading on and rebuild the cartridge. However, it wouldn't work if the pipelet referenced other classes.
The only reliable way of reloading classes is to use jrebel, it is a paid service, however. There are some free alternatives available, but I did not find any of them very reliable. You can also reload class by using the Eclipse debugger.