I am certain that these systems have been upgraded and well maintained.
The GEM+ missiles are highly capable against tactical ballistic missiles and cruise missiles.
The missiles are still in production with a contracted backlog of approximately 1,500 missiles and a near-term demand of an additional 1,000 missiles.
I do not know what Israel is replacing them with.
Below is a Wikipedia link with additional information on all Patriot configurations.
I would imagine that Israelis needs are more towards the ballistic missile threat which as I understand it the pac-3 missiles are better at. Does the basic system need to be changed to handle pac-3 and that would be why they are retiring these systems, or as you said already they have something better than patriot to replace them with?
Regardless Ukraine needs both capabilities desperately. Long range anti aircraft capabilities to push back/destroy Russian aircraft launching cruise missiles and glide bombs, and anti ballistic missile defense.
Pretty sure Ukraine won’t be picky
Hopefully Israel has a nice stockpile of AD missiles of any kind