Now that both Kasich and Cruz have left the race and Trump is still shy in the delegate count and there are still states to vote does the delegate count still apply?
Trump still needs to get 1237 delegates. If he doesn't, the convention could still nominate someone else. Cruz and Kasich withdrawing simply makes it easier for him to make that goal. In fact, failing to meet that goal under Republican voting rules would be very difficult.
Some states may unbind their delegates, as happened with Rubio. Other states may reassign the delegates to vote for someone else. As always, rules vary by state.
Note that the requirement is not 1237 pledged delegates. Uncommitted delegates could vote for Trump on the first ballot and some are expected to do so. Having 1237 or more pledged delegates is mainly useful in that it allows Trump to pivot to the general election secure that he will be nominated.