the 1552h is still available due to the requirement of some customers needing Class I, Div 2/Zone 2 certified, therefore will continue to be available.
If you do not need the Class I, Div 2/Zone 2 certification then you could use the latest range of outdoor AP's from 1540 / 1560 or 1570 series.
Alternatively, use an indoor AP from the 1800/2800/3800 range, within a Class I, Div 2/Zone 2 certified enclosure, available from third party suppliers.