I can’t speak for any of the Lubuntu team, but I can tell you that someone has made the decision to remove the Fancy Menu, and put the classic Application Menu back in.
Thank God that decision was made IMHO.
It has been explicitly changed, because plain LXQt 2.0+ (if installed from the sources) comes with the Fancy Menu by default.
I l-o-v-e Lubuntu (and LXQt even more). Unfortunately, since the merger of LXDE/Qt (the precursor of LXQt) with the original Razor Qt project, many years ago already, I have not seen many innovative things being added to the original Razor Qt / LXQt desktop since the merger. Perhaps some things under the bonnet have changed, and errors fixed. Unfortunately, besides of tonnes of translation-stuff not many new things.
Although, I come to the point now, the LXPanel application (the part of the desktop that more or less controls everything we do with the desktop) has seen an important innovation some years ago: one can drag and drop icons (applications) from the classic Application Menu into the quick launch area on the panel. In the LXDE/Qt and early LXQt days this was a bit more complicated, and not many people may have known how to achieve to put icons of frequently used applications in the quick launch zone. Now that works very easy!
There is no accounting for the taste of how a desktop should be organised.
I think using quick launch is superior to adding “Favorites” to the new gadget “Fancy Menu”. I think it is rather superfluous functionality.
Nothing fancy in fact.
So, I say… “hurray” to the person who decided to abolish the Fancy Menu in Lubuntu.