There's always that percentage of uncertainty for approving investing instrument such as Bitcoin ETF. And just as you speculated, other experts believes the same that approval might take more time. But this is not a bad thing really.
SEC being an institution that wanted to protect investors and the welfare of the general market and checking security points are well in place against fraudulent activities deferred the approval to get more time to carefully study the ETF proposal.
And should it take more time to be approved, we can all be sure that it is definitely for the better.