On the topic, will the $4000 FSD upgrade still be honoured with the upcoming autopilot hardware changes?
No one knows for sure. The investor call hinted that you should not wait for the new Model S. Model X and Model 3 to come with AP3 hardware in the Q2, so that would imply that you can still get FSD for whatever price it is now (it's an off menu item).
I would suspect that once AP3 hardware is ready, EAP and FSD will be combined into a single SKU at time of purchase for all new orders, and I would guess that the cost may go up.
On the same Investor Call, he did say the cost to build/mfg AP3 vs. AP2.5 will be nearly the same...
I also got the impression that once everyone has 2018.42.2, that might be the last feature of EAP, and going forward he will start to get ready the first feature set of FSD in line with the AP3 hardware upgrade for those who have purchased FSD already.