This is probably a more broader subject than just football rights but I think we're going to see more and more changes to the way subscription tv is offered in the future. As
@MissChief touches on, Sky have already fragmented their offering into smaller packages so people can pick and choose what content they want to pay for and what they don't. With Amazon moving into sports and with DAZN growing all the time, that's only going to put Sky under more pressure to be even more innovative with how they offer their content. I'm sure it won't be long before we'll be able to buy PL football from Sky, BT, Amazon or whoever else without having to pay for every other sport and or having to pay for their 'entertainment packs' too. Obviously if you're the person that wants all the entertainment packs, movies and every sport from every provider you're probably going to be worse off but hopefully it'll benefit the majority.
It's an interesting subject, one which Sky is well aware of. Sky has, recently anyway, looked at some of it's competitors and decided 'lets work with these guys' rather than continually fighting with each other. Sky's deal with Netflix and complete integration into the Sky Q box is unheard of and is also the first time Netflix has allowed such integration. That Sky and BT Sport are also working together to bring BT Sport to Sky and allowing it to be retailed by Sky (which looks like it may be finally happening in Jan or Feb next year) shows what a great position Sky is in.
The acquisition of UK La Liga rights by Eleven Sport and the subsequent puling and redistribution of those rights show that the overwhelming majority of people still want to watch Sport on a big screen, sitting on a comfy sofa, not on a tablet, laptop or Mobile phone if they can avoid it. Sky have a steady and slowly increasing userbase of customers that can be retailed to with an already existing distribution network readily available. It's the reason Boxnation, Premier Sport, Racing UK and even BT Sport themselves are on the Sky Platform. Sure it may not be particularly cheap, but it's still a lot cheaper and gives more potential customers than any other distribution method, as Eleven Sport found out. It will certainly be interesting to see how many people watch the Amazon Christmas Football matches as this will no doubt give a big indicator of Amazon and if they think showing more matches can be beneficial to them.
It should also be noted that many people here and elsewhere have been proclaiming Sky's demise for several years now but they consistently buck that supposed trend and help keep them gaining customers with new content and new Hardware. I can't see them disappearing any time soon and now with Comcast investment (which means no paying for NBC shows and likely having an exclusive on every NBC show as well as Universal films and their back catalogue) available they may even start to expand into the rest of Europe too.
Now TV is expanding massively within Sky with a lot of hiring going on, is going to 1080p soon (4k/UHD is likely a long way off to not step on the Sky Q offering) and will likely roll out into the rest of Europe soon.