No it isn’t. It is only the method that can be different. For that matter, any Protestant who is baptized using the trinitarian formula (“I baptize you OR the servant of God is baptized in the name of the Father, and of the Son,and of the Holy Spirit/ Ghost”) is validly baptized.
When you mean “East” do you mean those Churches loyal to the Holy Father, such as Byzantine; or do you mean Orthodox? Either way, the baptism is valid.
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