Difference being is that in scripture we are instructed to pray with others here on earth.
Paul advocates to always keep on praying for ALL the saints (Eph. 6:18); he makes no requirement that they must be alive. Frankly, I’m happy to think those saints who’ve gone on ahead, and now see clearly, are continuing to uphold Paul’s exhortation and pray for me; they surely can pray more accurately knowing what they now know. For my part, I pray for them that they enjoy fullness of life and love in their abode.
So long as it’s a praying FOR — not praying TO — the saints, there’s no biblical issue with it. The more the merrier.