Foreign players will likely be included in the amateur draft, but it's still in the negotiation stages with the MLBPU and MLBO.
When someone states "take the money while you can", that statement has been going on since the 80's to be honest with you.
The number of MLB free-agents signing this year will add more players in the compensatory/sandwich pick parts of the first, second and third rounds. The slotting system has not been adhered to by all MLB teams and MLB has bent a bit to allow over paying past slot recommendations. If the MLB office, Owners and Union can agree to bonus signing limits (doubt this will ever happen) then perhaps some consistency in bonus payouts will occur, again doubtful.
Slotting imho is never going to be agreed upon as long as bonuses are publicized and there are agents.