Pasting in the results of Googling a word is unacceptable on ELU for many, many reasons. This has been covered elsewhere, but here are a few of them, in no particular order:
It does not meet the network-wide requirements for referencing other’s work.
You have to provide a link when pasting in someone else's work.
You have to cite where the information comes ...
To answer your question of why it hasn't been done yet: It had not been requested before.
The number of downvotes here indicates that the community does not support this plan. Therefore, it is safe to conclude that it won't be implemented.
I'm marking this status-declined because it is not possible for us to re-open a failed migration stub that bounced back.
The solution is simple: if you wish to cite the OED, then by all means please do so. But Googling is not the OED. QED.