I too am seeing this condition.
Latest stable firmware MX 14.53
We have ~150 MX60/64s
None are showing the SD-WAN policies
Only IP Flow Preferences.
Our standard configuration is to prefer WAN1 and only use WAN2 in a failover mode.
I have tested enabling load-balancing and active-active VPN to see if any change but none.
I do have a pair of MX84 in Asia and they DO have the proper options but are only network I can find that does.
Opened case with Meraki and they are coming up empty initially and continue to research.