Could Verisign block the next new gTLD round?

I like to read that letter from the co-chairs of the GNSO’s policy development process on new gTLD subsequent procedures: it is positive and asking the right questions to ICANN. One paragraph caught my attention:

"We would also appreciate input on the total number of TLDs that could be delegated without negative impact to root server performance."

Honorable "new gTLD Boss" and ICANN CTO gave answers and I stopped on that section of a paragraph:

"There are also technical limits placed on capacity by the systems that handle root zone provisioning (operated by PTI as JANA Functions Operator and Verisign as Root Zone Maintainer)..."

Actually, I fell from my chair and broke two legs.

Verisign is the registry for ".com" domain name and has shown signs that new gTLDs were impacting its business: the more new domain name extension spread online, wider is the choice and - unless I am wrong - this reduces the choice to register a ".com" domain name.

I didn't know that the technical infrastructure of domain names relied on Verisign too but I believe that this could be used as a technical reason not to push for another round of new gTLDs.