"[A] sponsor may want to amend its qualified retirement plans to provide additional benefits and protections for participants with same-sex spouses, such as offering a new joint and survivor annuity election in cases where the participant was previously required to begin receiving a single life annuity. Because these would be discretionary and not mandatory amendments, [Notice 2015-86] cautions that the amendments would be subject to the same funding restrictions (for defined benefit pension plans) and nondiscrimination tests that apply to all discretionary amendments.... For [health] plans that do offer spousal coverage ... the Obergefell decision may require the plan to recognize additional same-sex marriages and to extend coverage to additional spouses."