Can someone please explain me all the new features that comes with latest 23.1 release including the cloud functionalities?

I think there is no central document explaining all Orcad X features and in which product they exist. 

On the PCB layout side. If you have an Orcad X license you gain access to the new Presto Editor. With Orcad license you only have Orcad PCB editor. At this moment, there is no cost to upgrade from Orcad to Orcad X, but it might change in the future. I usually go to parasys website (www dot parallel-systems.co.uk slash matrix) to see the features difference between Orcad , Orcad pro and Allegro. But it is not complete; it does not cover the added functionalities of Presto which are very very interesting. It is not documented but Presto Professionnal constraint manager includes several high speed features that were only available in Allegro up until now. I have found the following added features: max via count per net, adjacent layer keepout on package pins, return path check, relative propagation time. There must be other hidden gems that I did not discover yet.

But Orcad Presto is not complete yet, I still need Orcad PCB editor to use certain features. It is understanble since Presto has a minimalist interface to reduce number of click and menu depth. 

I think there is no central document explaining all Orcad X features and in which product they exist. 

On the PCB layout side. If you have an Orcad X license you gain access to the new Presto Editor. With Orcad license you only have Orcad PCB editor. At this moment, there is no cost to upgrade from Orcad to Orcad X, but it might change in the future. I usually go to parasys website (www dot parallel-systems.co.uk slash matrix) to see the features difference between Orcad , Orcad pro and Allegro. But it is not complete; it does not cover the added functionalities of Presto which are very very interesting. It is not documented but Presto Professionnal constraint manager includes several high speed features that were only available in Allegro up until now. I have found the following added features: max via count per net, adjacent layer keepout on package pins, return path check, relative propagation time. There must be other hidden gems that I did not discover yet.

But Orcad Presto is not complete yet, I still need Orcad PCB editor to use certain features. It is understanble since Presto has a minimalist interface to reduce number of click and menu depth. 

Yes that is correct