AP offers this report, quoting Candice Hoke:

Candice Hoke, an election law professor at Cleveland State University, said the sale raises questions about the consolidation of election services. “It’s a massive consolidation of voting-system vendors,” she said.
The increased size and influence of ES&S could make it harder for smaller, innovative companies to enter the market, she said. “The market power (of ES&S) will be so significant,” she said.
At the same time, Hoke said, ES&S’s growth could allow it to spend more on research to develop better voting machines.