Actually, my husband's employer-provided not junk plan was cancelled too. It was nonconforming because the OOP max for the family plan was three times the individual deductible and the ACA limits it to two times. Nearly every policy in the land used to use 3 times the individual limit on a family policy. Other people I know with not junk policies got the letter because they didn't have maternity coverage in their plans which all plans must now have regardless of the age (sex?) of the insured. They're also now required to cover some pharmaceuticals that they'd previously disallowed.
The insurance companies took these nuances and cancelled many, many plans that were just fine, but less profitable, and rewrote them in a way that a) increased the deductibles so that 2 times the individual deductible was closer to the previous 3 times the individual deductible and b) increased the copay on meds to offset the cost of the third tier of meds.
We're one of the lucky ones. Our silver plan covers less but also costs less. What was an 80/20 plan with a $30 OV copay and $3000 deductible for $1700/month will become a 90/10 plan with the same $30 OV copay and a $2000 deductible at $1400/month. The out-of-network coverage is now zero, however, for both inpatient services and outpatient. Drug copays are much higher.
edit: the plan recommended by the insurance company was a 70/30 plan with $50 OV copays and a $3000 deductible for $1350/month. Because it's a small company we were able to have input into which replacement plan was chosen and requested the 90/10 plan.