As said, not necessarily an issue in your specific configuration, but it may give issues when other (non-Mikrotik) devices are on the network, and also :
http://forum.mikrotik.com/t/management-vlan-issue/175412/1
If you prefer, in some cases VLAN1 can create issues, since it costs nothing to not use it, it is usually advised by the more expert people on the board to never use it.
Besides:
https://help.mikrotik.com/docs/display/ROS/VLAN
The IEEE 802.1Q standard has reserved VLAN IDs with special use cases, the following VLAN IDs should not be used in generic VLAN setups: 0, 1, 4095
BTW in the same page some examples do use VLANs with vlan-id=1 … 
In usual IEEE terminology, “should not” is not the same as “must not”, the latter means “do not” in absolute terms, the former is milder and means “do not, unless you really know what you are doing”, still even if the Mikrotik examples are valid exceptions to the rule, it is not IMHO a good idea to provide samples using values that may create issues.
But it is not like you have a much limited number of choices, 2 to 4094 should be enough.