I have FreeBSD and I had Calligra installed for testing but I had something which bother me:
I started with Krita which I like very much. But when I restart KDE Krita start too. I deleted some files in /local/.kde4 and was okay. Than I try Word and the problems was the same as with Krita.
With Word I open a file made with MS Word (simple) and was okay. Than I open with one MS Exell file and conversion was very bad.
I uninstalled Calligra because of autostarting Word/Krita and I diidn't find why.
Maybe next version will be better...
Almost forgot, I had the last version of Calligra.

Thanks.

There is nothing in Caligra itself that causes autostart as you call it. However if you don't close your apps before logging out yoy have experienced sessionmanagement where the desktop restarts non-closed apps when you start again.

It can be configured to not happen, but if you normally use gnome i don't know if the sessionmanagement of the kde desktop software is still operational somehow.

To change the behaviour on kde desktops go to kde system-settings - system administration - session manegement

Another thing which can cause this behaviour is applications continuing to remain in the background, either through intention (unlikely with Calligra) or because they have otherwise hung while exiting. The fix in this case is to kill them using the System Activity utility, accessible through Alt + F2 (KRunner - Run Command) under a Plasma Workspace.