You cannot get hold of the staff at RG by asking a question here. Speaking for myself, I would like also to see the Abstract in English, to save me from having to trust Google Translate.
Previously, I saw here in the RG many publications in Arabic, French, Russian, and Chinese. Therefore, adding non-English publications is OK from RG policy point of view, but this will significantly limit the general audiences regardless of the value of the publication. Adding an English extended summary would be very helpful to interested readers. I have some publications in Arabic, but didn't add them here due to the same reasons.