I suspect this is the case. "There's no guaranteed money in the second round" is a common refrain, but in practice many second rounders end up with substantial guaranteed money. The kicker is that there isn't a salary cap exception for second rounders like there is for first rounders, so teams need to use cap space or some other exception (e.g., part of the MLE).
Based on some quick research:
Last year, there were 23 players drafted in the second round out of the NCAA (the other 7 were foreign stashes).
- 12 signed contracts guaranteeing them over $2 million (for reference: the last pick in the first round got $3 million of guaranteed money, Tyler Lydon got about $3.5 million as the 24th pick)
- Another three got some guaranteed money as part of an NBA contract.
- Six of the other eight got 2-way contracts.
That leaves only two that were left completely without an NBA contract: Jaron Blossomgame signed a G-League contract with the Spurs' affiliate after they drafted him, Nigel Williams-Goss went to play in Europe.
TLDR: A lot of second round picks do pretty well for themselves, if they end up with a team that's committed to them.