FUBAR-BDHR
You are overly clever? Download and check this magnet.
And it is 1st April. This might be a lot of things and not blockchain data. You have to excuse people for being cautious about it.
And in addition now when we can run Bitcoin Core in prune mode there is a little less incentive to download blochaing data.
Copying the data directory (pointing Bitcoin to it) and not doing anything else won't pose much risks to the user. However, it isn't too good to rely on a stranger's files since the client won't be verifying all the blocks.
Even if one uses pruning, the Bitcoin client will still download and verify all the blocks before deleting older blocks. This could help to speed up the download and verification process.