How can we make an animated strike through on react native text?

Unfortunately, you can't animate strike directly but I used some tricks to achieve the same effect.

import React from 'react';
import { Animated, Easing, Text, View, StyleSheet } from 'react-native';

export default function App() {
  const ref = React.useRef(View.prototype);
  const animatedValue = React.useRef(new Animated.Value(0)).current;

  const [textWidth, setTextWidth] = React.useState(0);
  const [textHeight, setTextHeight] = React.useState(0);

  React.useEffect(() => {
    ref.current.measure((x, y, w, h) => {
      setTextWidth(w);
      setTextHeight(h);
      animateStrike();
    });
  }, []);

  const animateStrike = () => {
    Animated.timing(animatedValue, {
      toValue: 1,
      duration: 2000,
      easing: Easing.linear,
      useNativeDriver: false,
    }).start();
  };

  const strikeWidth = animatedValue.interpolate({
    inputRange: [0, 1],
    outputRange: [0, textWidth],
    extrapolate: 'clamp',
  });

  return (
    <View style={styles.container}>
      <View>
        <Text style={styles.text} ref={ref}>
          Some Dummy Text
        </Text>
        <Animated.View
          style={[
            styles.strike,
            { width: strikeWidth, top: textHeight / 2 + 1 },
          ]}
        />
      </View>
    </View>
  );
}

const styles = StyleSheet.create({
  container: {
    flex: 1,
    justifyContent: 'center',
    alignItems: 'center',
  },
  text: {
    fontSize: 20,
    fontWeight: '400',
  },
  strike: {
    position: 'absolute',
    height: 2,
    backgroundColor: 'red',
  },
});

You can check the demo here.

There is no way to achieve strikethough text with animation but you can customize it with the way like it's doing here Text animation with CSS - strike through line

You can create custom horizontal ProgressBar and animate it with absolute on Text so It might look the same you want.