I think the 2/3/25 date would still apply to Form 5500. Note that the release provides that "This means, for example, that the Feb. 3, 2025, deadline will now apply to:"... so the examples they provide (which do not mention Form 5500) are merely illustrative and not exhaustive. Like you said, all the other IRS releases include specific mentions to Rev. Proc. 2018-58 and include an "affected taxpayers" section (e.g., like in this one issued just 3 days prior: https://www.irs.gov/newsroom/irs-announces-tax-relief-for-taxpayers-impacted-by-severe-storms-and-flooding-in-new-york-various-deadlines-postponed-to-feb-3-2025). Notice that both IRs provide lead-in sentences about "applicability" to the effect that "These taxpayers now have until Feb. 3, 2025, to file various federal individual and business tax returns and make tax payments." The statements are IDENTICAL. If Form 5500s are covered under the NY announcement, then I think it's reasonable to think they also apply to the LA announcement.