No.
BTW, not sure if you may be misinterpreting this study. All the study shows is that in the presence of higher levels of E2 (estradiol), GHRP-6 mediated PRL release is greater. Thus in female rats that have a higher E2 than male rats, PRL release was greater. Also male rats that were supplemented with exogenous E2 showed similar increases.
GHRP-6 is not involved in increasing or decreasing E2 at all as it has no obvious pathway to do this, at least as far as this study is concerned.
Take Care.