It has not yet ended. There are still priests today. I'm a
redeemed firstborn.
It doesn't say that non-Jews would become priests, it says that non-Jews would serve G-d.
That doesn't seem like a good presumption. If that were true, then why are they receiving these comforting words in the same category as the non-Jew? There is nothing in the passage that suggests this.
Just the opposite, the chapter starts off praising the one who follows G-d's commandments.
Then it goes on to say that the non-Jew
shouldn't say, "[what's the point of keeping G-d's commandments?] G-d separated me from His nation[, so why should I join them?]".
And the eunuch shouldn't say, "[what's the point of me keeping G-d's commandment?] I'm a dried tree [and will have no continuity after I die anyway]"
G-d answers each of them according to their problem. To the eunuch G-d says, you
will have continuity. And to the non-Jew G-d says, you
can join the nation.
Its obviously saying that the eunuch was in the wrong before.
By what accounts? All it says is that he shouldn't marry and have children "in this place". This place being Anathoth, since the children born there were destined to die (see Jer. 11:21-23).
Even if that weren't true, the fact that G-d commanded Jeremiah to not marry and have children would indicate that G-d
wanted everyone else to get married and have children. Otherwise Jeremiah wouldn't need his own separate command for that.
Seems pretty different.