Short answer: No. Disability income coverage is an excepted benefit in all circumstances, so the health plan market reforms and HIPAA portability rules do not apply. The plan is still usually an ERISA welfare plan with plan document, SPD and claims procedure duties.
29 CFR 2590.732(c)(2) lists disability income coverage among the benefits excepted in all circumstances. The health plan reforms, such as the pre-existing condition ban and the preventive care mandate, do not apply, and offering STD or LTD is not an offer of health coverage.
It is still an employee benefit plan. An employer-sponsored STD or LTD plan is generally an ERISA welfare plan unless it is a government or church plan, a plan maintained solely to comply with a state disability law (29 U.S.C. 1003(b)(3)), or a truly voluntary arrangement under the DOL safe harbor. It needs a plan document and SPD and must follow the disability claims rules in 29 CFR 2560.503-1.
Disability coverage also carries no COBRA right, because COBRA reaches only plans that provide medical care.