Speeding up Karma gain with the lower start can help them 'hit their stride' faster than...2 years of RL gaming. I'd agree that 200 BP is a little low.
Is the theme of the game going to be like a 'Master/Padawan' thing where the PC's are young (because 200 BP doesn't even really cover a wage slave or even come close to being able to build any of the Contacts...and if you can't even be a Blogger...eep)
Time Skips can be another good way to justify some heavy karma awards. Start at 8 where all the PC's meet at a boarding school, have a (mis)adventure, skip 5 years to when one of their favored teachers gets extracted by a group of shadow runners and they try and fail to stop that, but in doing so get some clues, get a mission, etc. Another two years pass as they form a plan to leave, go off grid, become SINless, find where the teacher wound up...
Do the players have an in game view of what their 200 BP characters would be? Do they see themselves as skilled adults, just scaled back? Are they all underachieving slightly below average corp salary men that start their heroic journey when they are pushing 30 rather than the classic 'rite of passage' cusp of adulthood start?
Another way you could run with it is have the team have been competent and then they were selected (kidnapped, recruited, tricked, whatever) to be part of some new magically mojo science project and they come too jacked up beyond belief. Loss of memories, body is a wreck, skills forgotten, etc.
Then throw them into the fire, which will be utterly challenging as it'd be rather 'normal' level of threats, but with their reduced prowess, that's upgraded to 'just shy of being impossible.'
They fuddle through that and as they do, they go to the clinic, get some some pain meds, have a trigger circumstance and "old" skills start coming back to them in a rush. Their body adapts to whatever happened and their muscles repair. A quick trip to the Cyberdoc and he's able to reboot all that 'junk' ware in their body and suddenly they're back in tip top SOTA shape. This would let you dump targeted massive upgrades to them as you point at a character and go 'gain three strength right now.' Depending on the level of group trust there is, you could really give some odd development awards too, like giving the Hacker the +3 natural strength bonus so they can have some rather organic and non-standard builds or something.
And of course whoever did the experiments remains interested in them. Maybe split factions in it, some wanting to see how the PC's recover on their own so they are just 'tagged and watched' from afar. Maybe lending some support behind the scenes (which could be an amazing way to help bail out the underpowered PC's when they get in over their heads without it being some arbitrary hand of god thing where all of the Security guards suddenly got downgraded to 2 Agilities, no SGLs, and level 2 pistol scores.)
And to counter the 'helpful' faction, there is the group that wants them contained and brought back in for examination so there is internal conflict with 'Organization X.'