Will the SP3 support the new SP4 Type Cover?

[Windows Central Question]

Hi,
Long story short, I left my SP3 Type Cover in the car overnight and it got broken into and stolen. I was about to buy a new cover but upon seeing how nice the new keyboard design is I am thinking about just buying the SP4 cover. Does anyone know if it will still fit the SP3, as well as when it will be released?
Thanks.