I am not really sure if Digital Ocean stop this, really you'd need to open a support ticket to confirm, however I suspect they may do as I guess using ucarp it may be possible to hijack someone else's IP by using it as a Virtual IP, but as I said, please open a support ticket to double check.
However if ucarp is disabled have no fear, you can most probably achieve the same high availability and use of somewhat virtual IPs by having another droplet or two run HAProxy with some low TTLs in DNS in case one of the HAProxy droplets die. Let us know if you would like any further info with regards to this.
P.S. When you get your response from the support ticket please post any useful information here, it may help others with the same query.