You only have the option of adding AppleCare+ A) at the time of purchase B) within the first 30 days of purchase at an Apple Store or C) at the time of your *first* incident within the first year. If you pay $149 to replace the display, you are not offered the choice to buy AppleCare+. If you decide to pay $229 to replace the whole phone, you can add AppleCare+ for $49. If you decline and drop your phone again you do not have the option of adding it anymore. If you don't drop it till a year after purchase, even if it is your first incident you do not have the option if adding it. That is how it is currently.
As for the new plan, the increased service fee probably comes from the more expensive display cost since it incorporates the Touch ID sensor. Like the other apple employee, I have not heard anything official but my guess is that they will let everyone with AppleCare+ currently to continue to pay the $49 fee but for any future iPhone purchases, it will be $79. I also think the non-AppleCare+ fee will go up too so you're still saving the same amount of money by buying AppleCare+. Ex: currently with AppleCare+ it is $49 to replace a cracked display or a liquid danger phone. Without it, it's $149 for the display or $229 for the phone. My guess is that the new cost without AppleCare+ will be $179/$199 for the display or $249/$279 for the whole phone. This is just my guess because it makes the most sense to me.
Lastly, you can't just swap out the phone with AppleCare+ if it's cracked. Apple's new philosophy is they they will "fix" the issue chasing your phone to not work. That means if the only thing wrong is a cracked display, they will replace the display. If the enclosure is bent or split, or if the phone has liquid damage, then they will replace the whole phone.
