Microsoft is releasing Exchange Cumulative Updates every 3 months. CU 7 was released last September. CU 8 was released in December.

In Exchange 2016 CU 7, Install-AntiSpamAgents.ps1 Script Fails, I described how the CU7 Install-AntiSpamAgents script was broken. The script fails to install any anti-spam agents returning a long list of errors. Luckily the fix is very simple. You either get a copy of the script from an earlier Exchange 2016 CU or you just go ahead and edit the broken script directly. You will find all the details in my article describing the problem in CU7.

Considering how simple it is to fix, you would expect someone in Redmond would find the time to give this story a happy ending. NO, in 3 months no one bothered to open the script, position the cursor on line 50 column 164, hit the backspace 27 times and save the script.

So there you have it. For the moment you still need to fix this yourself.

UPDATE: Apparently it's going to be fixed in CU 9. This is what Brent Alinger [MSFT], had to say in a comment on the MS Exchange Team blog:
"This fix did not make Cumulative Update 8 but is resolved in Cumulative Update 9."

References

Exchange 2016 CU 7, Install-AntiSpamAgents.ps1 Script Fails

Released: December 2017 Quarterly Exchange Updates