packages to be removed; how to determine port conflicts?

[Gary Aitken]

Attempting to install node.js port (node10, node12, node14), I get this:

pkg install node10
Updating FreeBSD repository catalogue...
FreeBSD repository is up to date.
All repositories are up to date.
The following 29 package(s) will be affected (of 0 checked):

Installed packages to be REMOVED:
         FreeCAD: 0.18.4_10
         firefox: 80.0_3,1
         openshot: 2.5.1.236
         py37-qt5-webkit: 5.13.1_1
         py37-qt5-webkitwidgets: 5.13.1_1
         qt5-webkit: 5.212.0.a4_2
         thunderbird: 68.11.0_1

New packages to be INSTALLED:
         Box2D: 2.3.1
         c-ares: 1.16.1
         double-conversion: 3.1.5.19
         node10: 10.23.1

Installed packages to be UPGRADED:
...

Installed packages to be REINSTALLED:
...

Installed, Upgraded, and reinstalled seems ok, but removed is a problem.
How to tell why they are being removed?  FreeCAD was reinstalled two days
ago, so it seems like it should be reasonably up to date.  I get more-or-less
the same basic list regardless of which nodexx pkg I try to install.

Is this simply a matter of reinstalling after they are removed, or does this
indicate an incompatibility which will prevent installing at all?

Gary