Hey myself, I haven't thrown myself into one of these fan fights in awhile...
 
LETS START HERE!
 
Granted, your point is interesting. However, I'd like to disagree. 
 
Another match would kinda be just re-using material. It'd be pointless unless it could be scripted in, to which, the script would then have to shift to make sense for a Spinosaurus to be involved. 
 
Not to mention, Last I heard we weren't returning to the island. Either of them I'd reckon. 
 
So, That'd mean that the Spinosaurus would have to return in a totally forced situation. 
 
Following Cannon, INGEN abandoned that project for a reason, Besides having to ditch Site B. The Spinosaurus is shown as agressive, and very preditorial, this wouldn't have been good in a park setting, they would've made note of this in any and all reports before cancelling that project. 
 
Masrani Took over Ingen, Any and all property owned by them would've been noted by Masrani. 
 
Masrani wouldn't have cloned Spinosaurus, it may have been in development though, through manipulating certain traits you could possibly alter it's agressiveness, make it more docile. 
I feel the Subtle nod to it in JW was sufficient, it wasn't outright, but it was incredibly clever. 
Shameless self promotion, There used to be a running series on here about battling them both out.  Push comes to shove, It's a pretty even fight depending on the conditions. (I wrote that Just by the way, check me scified site) /end self promotion
 
I can tell you though, that it's actually a bit of writing importance that they had done that. The point was to make Spinosaurus the villain, He was, the big baddy. The one way to do that was to make people take this villain seriously. Best way to do that, have them kill someone. Rexy being the Beloved hero here, was the target. They did the same thing with I-rex actually, When it started to slaughter the Apotasaurs for sport. 
 
So, those are my Two cents on this ruccus.