Windows 10 Updates on Unsupported Computer

I have Dell 3620 that runs Win10 Pro.

But, looking at Dell's history of models and the time frames in which they have dropped support for the more recent Win10 updates from earlier models, it seems very likely that mine won't be supported for the May update, and certainly not for the fall one.

What happens when MS tries to install an update that's not supported by Dell on a computer? (You can only postpone updates for a certain length of time, even with Pro.)

Will the update fail?

Will the update install, but something on the system stop working - hw and/or sw?

Or is it a 'it depends' on the particular configuration of hw and sw on a given system? (I suspect that is the case.)

Is there a difference between what happens with the twice-yearly feature updates and the monthly updates in terms of impact on an unsupported system? ( I realize that the feature updates can be postponed for a longer period in Pro.)

Thanks for any insight.