If you edit a "needs review" transaction it will re-calculate cost basis on the account and clear the other 'needs review' transactions.
The remaining "needs review" transactions will not appear when searching. Other data such as loss/gain will also be temporarily unavailable.
This means users have to wait for the "needs review" transactions to reappear before they can continue making their edits.
Depending on the number of transactions on an account, this can make fixing transactions much more time-consuming than it would be if users were able to finish editing before the program does the recalculation.