https://em.countyofdane.com/pdf/2015_Project_Map.pdf
The HOR Super Sirex seems to be the only older siren to still be intact and left along. The rest of the older sirens (not sure about the three Model 7's near Monona though) are planned to be replaced. I don't know what the replacements will exactly be but looking at the range sizes for each of the new sirens, 6 will proably be
As for the other towns in the county including the Allertor in Cambridge and the :3t22: in Cross Plains, and maybe the Perf+Penetrator in Mount Horeb might be replaced too. However I highly hope the Perf+Penetrator stays as the only six of those ever made were in Dane County and the other five were already replaced.