As you can see by the relatively low Win Shares produced on average by No. 19 picks, the Hawks are unlikely to select a franchise player at that slot if they keep the pick. But a big part of building a championship team is assembling a roster around a superstar with players who are underpaid for their production. The best way to acquire such players is through the draft, because of the salary restrictions in rookie-scale contracts, and it's theoretically easier to find those players at No. 19 instead of No. 25.
The Hawks recently have had good luck with the No. 19 pick.
Their No. 19 overall pick in 2009, Jeff Teague, went on to become an All-Star point guard (once he finally got his chance to shine) and has produced 46.1 win shares over nine seasons. John Collins, the No. 19 overall pick in 2017, had a promising rookie season in which he produced 5.4 Win Shares.