For large-scale installations including more than just coax, does HDcctv require a "fork-lift upgrade" just like IP cameras?

No.

An IP camera installation tends to require a wholesale equipment change.
This is sometimes called the "fork-lift upgrade".

HDcctv preserves the existing investment in SD and IP cameras, while providing a plug-and-play for all cameras having a < 100m run on coax back to the DVR.
For the other SD and IP inputs, the customer gets a hybrid DVR with a great display.

Therefore HDcctv presents unique advantages to large-scale applications such as casinos or airports, delivering immediate benefits in a non-disruptive manner.

An open question is whether new coax is less expensive than a network to install and maintain. If pulling coax is acceptable, then HDcctv presents a compelling upgrade path for complex applications.