We know as much as you about when it is announced. An announcement on Monday would be sufficient time for e-div date this coming Friday. As for why did they waited is a guess, but my 2 cents says they wanted to wait until closer to the end of Q2 to have "hard" numbers for the quarter's earnings and estimated taxable earnings. They have the liquidity, but if it were me I would want hard numbers to guide the dividends, not projections.
That's pretty much why the Bloomberg article "Ares Capital Deal Deserves Cheers, Not Jeers" was written.
I did not dial into the conference, but when I get time I will carefully read the transcript. If the dividend is that much more stable then a bounce back is expected. There were other bidders for these assets, but paying 85 cents on the dollar, half of which will be in the form of ARCC stock, does not sound like they overpaid. Management will benefit, no doubt about that. But as long as I get something out of it, I won't complain. Of course results are yet to be seen... and this won't close for months.