I think the answer to this mystery lies in the fact that most streamers have been doing missions with half a skull or one skull in difficulty. Once we see streamers take on 4/5 skull missions we'll see Urbies coming out of the gawd-damned walls 
The list of variants was published too. There will be no HBK-4J unless you mod it into the game. No SHD-2K either.The mechs are weighted by rarity, it's in the JSON files. What troubles me is we haven't seen a single variant that wasn't in the beta files I don't think, and I know there is some stuff in timeline that we should be getting. Not even chassis but variants. The PPC Shadowhawk for example, or the Hunchie 4J.
plus something called a "BJ-1 Starter." Probably a dilapidated version.
Urbie OPDon't want to make the early game too hard.
Have they shown any base assault missions? That is where I would expect Urbies to show up, especially if it is a Capellan base.
I hope the mech distribution is linked to "where" you are. Meaning: If you are within the Conf. Capella, you see more Urbies since they are produced exclusively on Betelgeuse, a firm Liao-planet near the Marik-Border.
I think, most streamer played within the Periphery or did Story missions and chose not to engage against House Liao, which could explain the ... lack of Urbies as an Enemy.
They already get picked on enough, do you really want to land that blow on themCan I rename them the Acapella Confederation?
After the long and tedious search your team finally reached the Star League cache. Trembling with anticipation, you break open the ancient doors. Behind them lies your long-sought prize - a 6-pack of Urbanmechs in factory packaging.
I think Urbies were removed from earlies stages of game because they're cheap and easy source of AC-10s
The list of variants was published too. There will be no HBK-4J unless you mod it into the game. No SHD-2K either.
LIGHT
- Locust - LCT-1M, -1S, -1V***
- Commando - COM-1B, -2D***
- Spider - SDR-5V
- Firestarter - FS9-H
- Jenner - JR7-D
- Panther - PNT-9R
- Urbanmech - UM-R60
MEDIUM
- Cicada - CDA-2A***, -3C
- Blackjack - BJ-1 (plus something called a "BJ-1 Starter." Probably a dilapidated version.)
- Vindicator - VND-1R
- Centurion - CN9-A***, -AL
- Enforcer - ENF-4R
- Hunchback - HBK-4G***, -4P
- Trebuchet - TBT-5N
- Griffin - GRF-1N***, -1S
- Kintaro - KTO-18
- Shadowhawk - SHD-2D, -2H***
- Wolverine - WVR-6K, -6R***
HEAVY
- Dragon - DRG-1N
- Quickdraw - QKD-4G, -5A
- Catapult - CPLT-C1***, -K2
- JagerMech - JM6-A, -S***
- Thunderbolt - TDR-5S***, -5SE, -5SS
- Grasshopper - GHR-5H
- Orion - ON1-K***, -V
- Cataphract - CTF-1X
- Black Knight - BL-7-KNT
ASSAULT
- Awesome - AWS-8Q***, -8T
- Victor - VTR-9B***, -9S
- Zeus - ZEU-6S
- BattleMaster - BLR-1G
- Stalker - STK-3F
- Highlander - HGN-733***, -733P
- Banshee - BNC-3E***, -3M
- King Crab - KGC-0000
- Atlas - AS7-D
*** denotes the standard model, listed in the technical readouts (TROs).
The list of variants was published too. There will be no HBK-4J unless you mod it into the game. No SHD-2K either.
LIGHT
- Locust - LCT-1M, -1S, -1V***
- Commando - COM-1B, -2D***
- Spider - SDR-5V
- Firestarter - FS9-H
- Jenner - JR7-D
- Panther - PNT-9R
- Urbanmech - UM-R60
MEDIUM
- Cicada - CDA-2A***, -3C
- Blackjack - BJ-1 (plus something called a "BJ-1 Starter." Probably a dilapidated version.)
- Vindicator - VND-1R
- Centurion - CN9-A***, -AL
- Enforcer - ENF-4R
- Hunchback - HBK-4G***, -4P
- Trebuchet - TBT-5N
- Griffin - GRF-1N***, -1S
- Kintaro - KTO-18
- Shadowhawk - SHD-2D, -2H***
- Wolverine - WVR-6K, -6R***
HEAVY
- Dragon - DRG-1N
- Quickdraw - QKD-4G, -5A
- Catapult - CPLT-C1***, -K2
- JagerMech - JM6-A, -S***
- Thunderbolt - TDR-5S***, -5SE, -5SS
- Grasshopper - GHR-5H
- Orion - ON1-K***, -V
- Cataphract - CTF-1X
- Black Knight - BL-7-KNT
ASSAULT
- Awesome - AWS-8Q***, -8T
- Victor - VTR-9B***, -9S
- Zeus - ZEU-6S
- BattleMaster - BLR-1G
- Stalker - STK-3F
- Highlander - HGN-733***, -733P
- Banshee - BNC-3E***, -3M
- King Crab - KGC-0000
- Atlas - AS7-D
*** denotes the standard model, listed in the technical readouts (TROs).
- Blackjack - BJ-1 (plus something called a "BJ-1 Starter." Probably a dilapidated version.)
Definitely.Tutorial version?
@HBS_Kiva on Twitter about Urbanmechs:
I have to say I am curious about this. Given how much love the Urbie get's I would have expected it to be the most frequent mech second only to Locusts.