Curiosity about the new version of Rhino

I want to know if the code of intersection of the next version of Rhino is the same as that of Rhino 5? There are changes to the kernel?
If not, how ever repeats the same story, according to which many of the aspects that worked in Rhino 5, in Rhino 6 become bug? So you never stop!
Everything that worked before should continue to work, or not? Instead it seems to me that development is a continuous back and forth … (without controversy)
Thanks

Hopefully. However often when trying to fix bugs or develop new stuff, existing functions can get broken, but they are almost always fixed as soon as that is discovered.
–Mitch

Mitch is right. But let me quote Bob McNeel from another thread:

In other words: there will be changes to the core that might or might not require modifications to whatever you had coded for Rhino5. At least, Rhino5 and 6 plugins will not be compatible.

If you are talking about scripts or Python, you should be fine mostly, since those are another layer away from the core SDK.

Yes, what I said is only with regards to internal Rhino commands and nothing else. --Mitch