This is what is stated here: http://www.libreoffice.org/get-help/system-requirements/#Apple
Apple - Mac OS X
The software and hardware prerequisites for installing on a Apple Mac OS X computer are as follows:
Mac OS X 10.6 (Snow Leopard) or higher;
512 Mb RAM;
Up to 800 Mb available hard disk space;
1024x768 graphic device with 256 colors (higher resolution recommended).
It is a recommended best practice to back-up your system and data before you remove or install software.
For certain features of the software - but not most - Java is required. Java is notably required for Base.
Detailed information about Gatekeeper and OS version support may be found on the TDF Wiki.
The next release series (4.4) will require OS X 10.8+; Support for OS X 10.6/10.7 will end when LibreOffice 4.3 is retired on May 27, 2015.
The last 2 lines maybe the important information for you.
I installed recently LibO 4.3.4 on a MacBookPro and consider to upgrade to 4.3.5 ASAP.
You can keep using the LibO 4.3 version as long as you stick with your OS. 4.3 is a pretty good version.
As for the statement
Mac OSX 32 bits build and version 10.6 and 10.7 are deprecated.
I feel this could be a mistake in the 4.3 release notes. At least until now I did not observe a problem with 4.3.4 with OS 10.6