Isso não é verdade. Você pode configurar um balanceamento de carga HTTP e HTTPS para o mesmo VIP.
Exemplo de configuração:
rserver host web-01
ip address 10.x.x.x
probe SIMPLE-ICMP-PROBE
inservice
rserver host web-02
ip address 10.x.x.x
probe SIMPLE-ICMP-PROBE
inservice
serverfarm host 055-SFARM
predictor leastconns slowstart 120
probe SIMPLE-HTTP-PROBE
rserver web-01 80
inservice
rserver web-02 80
inservice
class-map match-all VIP:443
10 match virtual-address 10.1.1.2 tcp eq https
class-map match-all VIP:80
10 match virtual-address 10.1.1.2 tcp eq www
policy-map type loadbalance first-match VIP:443-POLICY
class class-default
serverfarm 055-SFARM
policy-map type loadbalance first-match VIP:80-POLICY
class class-default
serverfarm 055-SFARM
policy-map multi-match VIP-SPOLICY
class VIP:80
loadbalance vip inservice
loadbalance policy VIP:80-POLICY
loadbalance vip icmp-reply active
class VIP:443
loadbalance vip inservice
loadbalance policy VIP:443-POLICY
loadbalance vip icmp-reply active
ssl-proxy server SSL-PROXY-WITH-CERT