Rephrase paragraph about ARM MTE

Author: rcvalle

src/doc/rustc/src/exploit-mitigations.md

@@ -363,11 +363,12 @@ elements, invalid pointers, invalid sizes, double/multiple “frees” of the
 same memory allocated, and many corner cases of these. These checks are
 implementation specific, and vary per allocator.
 
-Newer ARM-based processors will provide hardware assistance (i.e., [ARM
-Memory Tagging Extension
-[MTE]](https://community.arm.com/developer/ip-products/processors/b/processors-ip-blog/posts/enhancing-memory-safety))
-to detect memory safety violations by tagging memory allocations, and
-automatically checking that the correct tag is used on every memory access.
+[ARM Memory Tagging Extension
+(MTE)](https://community.arm.com/developer/ip-products/processors/b/processors-ip-blog/posts/enhancing-memory-safety),
+when available, will provide hardware assistance for a probabilistic
+mitigation to detect memory safety violations by tagging memory allocations,
+and automatically checking that the correct tag is used on every memory
+access.
 
 Rust’s default allocator has historically been
 [jemalloc](http://jemalloc.net/), and it has long been the cause of issues