Seems not much planned related to MIDI in 2016

Could still be since the current upcoming list is specifically for Spring.   

Hoping in next 1 or 2 monthly updates at least declared before 31 March

Not ideal, but can you accomplish what you want today with linked clips and loopbe1?  I admit I haven't diagrammed this, and I'm not familiar with MIDI plug-ins you mentioned, but I think linked clips will get you there.
 
It would potentially be a lot of duplicate MIDI tracks, but it would also appear very straight-forward when you're trying to figure out what's what when you reopen the project after a month not looking at it.
 
I'm mentioning this as something you might be able to use in the mean time, not to talk you out of your request.

I forgot to mention that I want Instrument Tracks also to be listed so that we can route the MIDI / MIDI FX / Arpegiator.. Moreover I was thinking/visualizing we can do more than what we can do with 16 MIDI channels only.

I think it would also be useful to have a processor in the loop. For instance, MIDI filter, MFX plugs, CAL scripts?
 
I could envision a chord being filtered so the lowest note (root?) was latched for a period of time and used to trigger an arp track, multiple midi notes being remapped to trigger percussion assigned to a single note value on another track, MIDI CC values mapped to different parameters in different instruments and effects on different tracks, etc.
 
MIDI patching remains one of my most exciting feature requests.

I came here to suggest something like this.
I would like to see the arpeggiator to allow configuration to define an arpeggio per note.
And the hub to provide filters for each midi output channel - so lowest note to the bass sound  

BobF
Not ideal, but can you accomplish what you want today with linked clips and loopbe1?  I admit I haven't diagrammed this, and I'm not familiar with MIDI plug-ins you mentioned, but I think linked clips will get you there.

I have tried to program 2 things:
 
1) MIDI Hub as VSTi. Sonar supports MIDI output from VST, so I thought why not just route input MIDI to 16 outputs which can be used as input for other MIDI tracks. Result:
a) VSTi MIDI output is delayed by one audio buffer size. That is somehow in VSTi by definition, since MIDI was thought to provide input/control for next buffer.
b) plug-in delay compensation is not working well in this case, there is a difference between live MIDI input and track MIDI input, in the second case Sonar apply compensation, in the first case does not
c) MIDI routing get broken under some conditions, so even moderate setup is hard to keep in tact. Either Sonar detects "loops" or for other reason, but it changes input from VSTi output to Omni. That immediately generates real loop since VSTi midi outputs are also in Omni.... with Sonar crash as a consequence
d) since the number of MIDI sources explodes, correct routing is hard to achieve. Any mistake produce (c).
 
2) my second attempt was MIDI Hub as MFX. MFX are processed correctly and without delays (at the end that is the only "official" way to process MIDI). Result:
a) all my attempts to "inject" midi according to the documentation to something other as "omni" have failed. That injecting was thought to be used by DX instruments with keyboard in the interface, sure there was no intention to send MIDI to other track
b) MFXes from different tracks can be executed not in order I want (the source first, then other) and so I have not found reliable way to route MIDI apart from Sonar (using separate communication between plug-in instances). At least not at "perfect sync" level.
 

Wow AZSLOW.... You are in the thought? Now something will definitely come up.

What if MIDI Hub is neither VST nor MFX?
If Register array is used which will get updated triggered by any MIDI incoming msg? I don't know.. just a thought.
 
Regards
Snehankur