I don't think Apple cares much, actually. Most software that would depend on systemd is GUI, DE and such (like Gnome) - and they don't need this. Text-based tools will keep working just fine. And servers - do they still care about the servers?
FreeBSD will most likely just turn it down on the basis of poor architecture. It won't be the first time they go down a different route (see also: OSS/ALSA/PA), though this particular difference may well be the biggest yet. On the other hand, there's also that part of the Linux community that is unhappy with this change, and they look like they'll stick to their guns, even if the most popular distros will move on. Seeing how it coincides with unhappiness over Gnome and numerous attempts to fork or otherwise "sanitize" it, I think those two efforts will be combined. At the same time, KDE is in no rush to bet exclusively on systemd, either. Long-term, I think FreeBSD may well decide to ignore future Gnome versions, and focus on KDE as the heavyweight DE, and otherwise suggest that people use XFCE or other lighter alternatives. Slackware has been ignoring Gnome for a long time now (pre-3.0) so there is some precedent there.
On the server side of things, I honestly don't think that systemd-exclusive way of doing things is going to have much uptake. Server software will probably add some support for it, but not exclusively.